Case studies

  • Make of vehicle:

  • Symptoms:

  • Fuel type:

In this series a PicoScope automotive oscilloscope is used to diagnose vehicle faults. Fault-finding procedures, detailed explanations of components and systems, and high-performance automobiles make this high-octane series a must read.

Vehicle Case study Date added Fuel All vehicles All symptoms All fuel types
Vehicle Case study Date added Fuel All vehicles All symptoms All fuel types
Ferrari
360

Intermittent non-start
The car came in with an intermittent non-start complaint, but after quizzing the customer it became more of a “no crank” problem

28/04/2015 Petrol Ferrari Intermittent non-start Petrol
Lotus
Elise II

High idle speed and cutting out
The vehicle came in with a complaint of high idling and occasional cutting out.

28/04/2015 Petrol Lotus Cutting out,
Intermittent non-start,
Petrol
V8

Troubleshooting a knock sensor
The vehicle arrived with the engine MIL on but with no noticeable running problem. Checking the system with a scan tool, I found these diagnostic messages: Accelerator potentiometer, Knock sensor Cyl 1-2-7-8

28/04/2015 Petrol V8 MIL on but no symptoms,
Petrol
Lotus

2004

Intermittent misfire
The vehicle had an intermittent misfire and the engine MIL was on. I found the engine misfiring constantly, with excessive smoke issuing from the tailpipe, so I left it running for a little while to get a feel of the problem and to scan the system for trouble codes.

28/04/2015 Petrol Lotus Engine misfire (intermittent),
MIL on,
P0201,
Petrol
BMW
X5

Intermittent misfire
When the book-in came, I allocated more time than usual to this one...

29/04/2015 Petrol BMW Engine misfire,
Engine misfire (intermittent),
Intermittent non-start,
P0205,
Petrol
Audi
A2
2002

Heavy steering
I’d visited this 2002 Audi A2 once before with an intermittent problem of the power steering going heavy. During testing I couldn’t get the car to fail, and checking the system with the scan tool found no DTCs logged either.

29/04/2015 Petrol Audi Heavy steering,
Petrol
Audi
TT Quattro
2001

CAN Bus Fault
A 2001 Audi TT Quattro arrived in the workshop with a complaint from the customer of an intermittent ESP light. At first the fault was not obvious at all. We had heard that the ABS modules could be a common failure but I had to be sure before fitting.

29/04/2015 Petrol Audi CAN Bus error,
Intermittent ESP light,
Petrol
Subaru
flat 4 port and direct injection, non-turbo
2012

Cylinder misfire
An intermittent issue of the engine warning light illuminating and fault code “P0302 Cylinder 2 misfire” detected.

07/05/2015 Petrol Subaru Engine misfire (intermittent),
MIL on,
P0302,
Petrol
Unspecified

Low speed ABS fault
The vehicle came in with the complaint that the ABS could be felt working through the brake pedal at very low speeds. I carried out a short road test to verify the complaint and, sure enough, the ABS would cut in at very low speeds; in fact, just before the car came to a stop.

11/05/2015 Unspecified Unspecified ABS fault,
Unspecified
Unspecified

Scan tool communication fault
The car had an intermittent drivability complaint, bogging down under acceleration with no MIL flagging. The customer insisted that it wasn’t just intermittent; it was very intermittent.

11/05/2015 Unspecified Unspecified No OBD communication,
Poor acceleration,
Unspecified
Unspecified

Poor interior temperature control
The customer complained that the interior temperature would occasionally hang at one setting. He couldn’t say at which temperature this happened, just that sometimes it stopped working. I decided to investigate.

11/05/2015 Unspecified Unspecified Poor interior temperature control,
Unspecified
Ford
Escort
1999

Cranking with no start
This car was a 1999 Ford Escort 4 cylinder 1.6 litre and had been bought from a reputable used car lot with no apparent problem. After a few weeks the car had an additional inventory of lowered springs, alloys, up-rated stereo, and two big holes in the rear parcel shelf ready for some speakers.

11/05/2015 Petrol Ford Non-starter with cranking,
Petrol
Ferrari
355
1999

Surging at idle and poor running
This customer reported bad surging at idle when the vehicle was warm, general poor running, and repeat DTC logging of LH BANK FRONT O2 SENSOR and RH BANK FRONT O2 SENSOR.

11/05/2015 Petrol Ferrari MIL on,
Petrol
Seat
Arosa
2004

Non-starter
This vehicle had found its way to a specialist diesel shop with a no-start complaint. The car began by occasionally cutting out, but progressively got worse and eventually turned into a complete no-start.

11/05/2015 Diesel Seat Non-starter with cranking,
Diesel
Vauxhall
Astra
2001

Misfire under load
This Vauxhall Astra 1.6 had a misfire problem under load. The repair shop had diagnosed the coil pack as faulty and fitted a new unit with plugs, but this made no difference to the problem.

11/05/2015 Petrol Vauxhall Engine misfire,
P0300,
Petrol
Vauxhall
Zafira
2000

EGR valve
The customer complaint was intermittent cutting out. This was eventually narrowed down to only stalling at junctions: how important is correct information?

11/05/2015 Diesel Vauxhall Cutting out,
EGR fault,
Engine stalling,
Diesel
Vauxhall
Corsa
2004

Non-starter
This 2004 Corsa 1.2 arrived with dash and engine auxiliaries already stripped and its trims and covers in the boot. In fact the ECM was missing and had to be sourced from the previous repairer; so a good start.

11/05/2015 Petrol Vauxhall MIL on,
Non-starter with cranking,
P1615,
P1616 ,
Petrol
BMW
X5

Battery drain
This BMW had a complaint of intermittent no start caused by the vehicle battery discharging. Sometimes it would last two weeks and other times only last two days. The battery had already been replaced, twice, and the alternator overhauled and given a clean bill of health.

11/05/2015 Petrol BMW Battery drain,
Intermittent non-start,
Petrol
Fiat
Bravo
1999

Intermittent speedometer
The case was a 1999 Fiat Bravo 1.6L with a complaint of intermittent speedo operation. The speedo would read correctly up to cruise speeds then would suddenly drop to almost zero.

11/05/2015 Petrol Fiat Intermittent speedometer,
Petrol
Fiat
Punto

Electronic Control Module (ECM) failure
This Fiat Punto 1.2Lsuddenly developed a misfire and never recovered. It was driven to the customer’s own local garage, where they carried out the usual checks, and was starting to look like the ECM had failed.

11/05/2015 Petrol Fiat ECM failure,
Petrol
Peugeot
406
2001

Misfire
This Peugeot 406 came to me with a complaint of misfire, and had with it one of the most comprehensive shopping lists I’d seen...

11/05/2015 Petrol Peugeot Engine misfire,
Petrol
Fiat
Ducato
2004

Poor starting
The vehicle was a Fiat Ducato 2004 2.8 JTD with a repetitive complaint of poor starting. The engine would crank at good speed but took a while before it eventually fired, and once started the vehicle drove fine.

11/05/2015 Diesel Fiat Poor starting,
Diesel
Vauxhall
Corsa
1999

V6 Transplant
Ordinarily I wouldn’t have given this the time of day had it not been for an unusual recorded trace, which I felt would be interesting to share. The eventual cause of the fault was… you’ll have to see it to believe it.

11/05/2015 Petrol Vauxhall Engine misfire,
Petrol
VW
Golf 1.9 TDI
2003

Variable nozzle turbine pressure control
I was fortunate enough recently to get hold of a WPS500X Pressure Transducer and looked forward to using it right away. It didn’t take long before I found a perfect excuse to switch it on: the Variable Nozzle Turbine (VNT) boost control.

11/05/2015 Unspecified VW Unspecified
Unspecified

Diesel engine rebuild testing
The Michigan Army National Guard operates and maintains a very large fleet of heavy diesel equipment. It is imperative that this fleet be kept at a high level of readiness and reliability at all times.

11/05/2015 Diesel Unspecified Diesel
Audi
S2

Intermittent and progressive failure to start
The car was brought to us on the back of a tow truck, the owner reported that after running faultlessly for some four months after a new distributor had been fitted, one morning, for no obvious reason, the car would not start.

11/05/2015 Petrol Audi Intermittent non-start,
Non-starter,
Petrol
Alfa Romeo
Spider
1998

Misleading MIL
The vehicle arrived at the workshop because the MIL (Malfunction Indicator Lamp) was illuminated. The vehicle showed no other drivability issues.

11/05/2015 Petrol Alfa Romeo MIL on but no symptoms,
P0300,
Petrol
VW
Golf

Misfire
This VW Golf (1.8, 20 valve, turbo, engine code AGU) was presented to me with the fault described as a misfire at 2000 rpm.

11/05/2015 Petrol VW Engine misfire,
Petrol
BMW
5 Series
2000

Braking fault
A 2000 model year BMW 5 Series was brought to us with the ABS/ESP light illuminated, following unsuccessful diagnosis and repair elsewhere.

11/05/2015 Petrol BMW ABS fault,
ESP fault,
MIL on,
Petrol
Vauxhall
Signum
2003

Misfire
A 2003 Vauxhall Signum arrived at the workshop with a slight misfire and general flatness under acceleration. A scan provided the code P0301 (Cylinder 1 Misfire Detected) and a quick inspection confirmed that the insulation had failed on the cylinder 1 coil area.

11/05/2015 Petrol Vauxhall Engine misfire,
P0301,
P1191,
Petrol
Toyota
Avensis
2002

System too lean
A 2002 Toyota Avensis came in with the MIL on and two DTCs present: P0171 and P0174 System Too Lean on banks 1 and 2 respectively. On the first visit I was asked to clear the codes (it was a motor trader’s car!) which I did, with the suggestion that it would most likely return.

11/05/2015 Petrol Toyota MIL on,
P0171,
P0174,
Petrol
Ford
Focus
2003

Hard to start from cold
I had a 2003 Ford Focus 1800 TDCI Duratorq come in with a hard start issue from cold. Once it was warm it would start great every time. No DTCs stored and live data showing good pressure generation.

11/05/2015 Petrol Ford Poor starting,
Petrol
Audi
A6
2001

Battery discharge
Recently I was faced with a customer who had completely given up on the idea of her car ever being fixed. The lady owner of a 2001 Audi A6 1.8 Turbo, explained to me how she has always had problems with the battery discharging.

11/05/2015 Petrol Audi Battery drain,
Petrol
Smart
ForTwo
2004

Misfire
This story concerns an employee of Pico Technology and their journey to the office. About one mile from work the owner of this 54,000 mile Smart Fortwo started to experience a very noticeable misfire.

11/05/2015 Petrol Smart Engine misfire,
Engine stalling,
Petrol
Dodge
Ram
2003

Catalytic converter
Recently I had a 2003 Dodge Ram 4.7 litre V8 booked in with the MIL reporting a problem. With only OBD connectivity I managed to pull P0420 catalyst efficiency bank 1.

11/05/2015 Petrol Dodge Heavy steering,
P0420,
Petrol
Skoda
Octavia

Crankshaft reluctor
This vehicle was recovered from another garage after having its engine rebuilt. It would start and then cut out.

11/05/2015 Petrol Skoda Engine stalling,
Petrol
Audi
A8
2003

Injector fault
A 2003 Audi A8 was having a problem with rough running which in turn was causing the engine management light to illuminate.

11/05/2015 LPG Audi Cutting out,
P0204,
P0300,
P0304,
P1130,
P1138,
LPG
Peugeot
406
2001

Low Power P0191 P1138 MIL
Intermittent faults are the bane of our lives in the garage. Recently though we were fortunate to have the scope set up whilst a problematic Peugeot faltered before our eyes, thankfully the scope was gathering data.

11/05/2015 Diesel Peugeot MIL on,
P0191,
P1138,
Poor acceleration,
Diesel
BMW
M3
2003

Electrohydraulic gearbox control
Knowing when to say “No!” is something that we learn as we progress through the ranks in the motor repair business, but sometimes we still succumb to the urge to take on an interesting job. We recently had a 2003 BMW M3 drop in on us, with two warning lights displayed and the customer complaining that he kept losing his gears.

11/05/2015 Petrol BMW P1717,
Petrol
Mercedes
W140 S-Class
1995

Intermittent misfire
The Mercedes W140 S-Class V8 engine had developed an intermittent misfiring fault. The misfiring could be observed during idle speed when the engine was warm – however it was not a serious issue. Within a month it became apparent that as the engine coolant temperature reached 60 °C, the ‘intermittent’ fault became permanent.

11/05/2015 Petrol Mercedes Engine misfire,
Engine misfire (intermittent),
Petrol
Audi
S3
2001

Rough idle
In July of 2010, a 2001 Audi S3 came to us with idling problems. To our disadvantage, a garage had previously worked on the vehicle and cleared the ‘DTC’ (Diagnostic Trouble Code) information from the ECU.

11/05/2015 Petrol Audi P0102,
P0133,
P1114,
P1137,
P1296,
Petrol
Ford
Explorer
2002

Intermittent misfire
This is the tale of a 2002 Ford Explorer with an idle quality complaint. According to the customer the idle would surge, especially when first started and would even stutter a bit when put into gear. As the engine warms up, the problem fades and is much less noticeable.

11/05/2015 Petrol Ford Engine misfire (intermittent),
Poor idle,
Petrol
Proton
Impian

Intermittent non-start
A Proton Impian was suffering from intermittent starting problems, and the vehicle randomly cut out. This caused the engine warning light to illuminate.

11/05/2015 Petrol Proton P0340,
Petrol
BMW
E46 318i
2000

Non-starter
The vehicle had been driven through a flooded area, and water had entered the block via the air intake. The car cut out with the engine flooded with water. The cold water entered the hot cylinder block, and caused it to crack due to thermal shock. The engine had been replaced, but could not be started.

11/05/2015 Petrol BMW No OBD communication,
Non-starter,
Petrol
Ford US
Windstar
1996

Misfire
Technician and workshop owner Rich Barton of Iowa, USA, was shown a 1996 Ford Windstar minivan that ran well when cold, but misfired badly when warmed–up.

11/05/2015 Petrol Ford US P0174,
P1537,
Petrol
Chrysler
Concord

Misfire
This Chrysler Concord (coil over plug system) came in with a cylinder–specific misfire problem. With some testing I found that the number 5 coil had no spark.

11/05/2015 Petrol Chrysler Engine misfire,
Petrol
Hyundai
Porter
2006

Cold start problem
This car had a cold start problem, where the engine ran poorly and white smoke was apparent. The previous engineer had changed injectors and the actual engine head, however the problem still occurred.

11/05/2015 Diesel Hyundai Poor starting,
Diesel
Audi
A6
2006

Engine cutting out
The car came to us from a transmission repair center. The problem was an occasional engine cut–out during cold cranking. It is difficult for technicians to investigate this particular problem due to it occurring during cold cranking.

11/05/2015 Petrol Audi Engine stalling,
Poor starting,
Petrol
VW
Golf
2001

Rough running
The car came to me after the previous repairer had spent a week or so head–scratching and internet–searching.

11/05/2015 Diesel VW P1248,
Diesel
Peugeot
206
2006

Misfire
When cold starting this car would misfire, but when warm it quickly cleared. No misfires occurred under normal driving conditions.

11/05/2015 Petrol Peugeot Engine misfire,
Poor starting,
Petrol
VW
Bora
2002

Faulty air mass sensor
Strange engine behaviour between 1200 rpm and 3000 rpm. There was a little bit of engine knocking and some misfire — with black smoke coming out of the exhaust pipe. The engine had a fluctuating idle rpm — sometimes worse than others.

11/05/2015 Diesel VW Engine misfire (intermittent),
Poor idle,
Diesel
BMW
Mini
2001

K–Bus diagnostics
The vehicle was left with me and I was able to put a diagnostic plan in place. The vehicle started and drove fine, the TPMS is a manual reset function and would not reset.

11/05/2015 Petrol BMW Airbag light,
Tyre pressure monitor,
Petrol
Mercury
Sable
1991

Surging at idle
Engine generally idled okay until it was shifted out of Park, and then it started surging. Going back into Park did not return to a better idle and continued to surge.

11/05/2015 Petrol Mercury Engine stalling,
P0326,
Poor idle,
Petrol
Rover
45
2004

Rover 45 with MIL on, P0170 Fault Code
This car came with the MIL (Malfunction Indicator Lamp) illuminated but no reports of any running issues. The first action was to read the PCM (powertrain control module) for the stored code(s). There was only one stored.

11/05/2015 Petrol Rover MIL on but no symptoms,
P0170,
Petrol
BMW
325i E36
1991

Poor performance
I was presented with this 1991 6cyl E36 325i BMW which had an on-going problem for the last two years and it seemed repairable. The complaint was lack of power, hesitation and the occasional cutting out on acceleration once warm.

11/05/2015 Petrol BMW Poor acceleration,
Power loss,
Petrol
Ford
S-Max
2010

Sudden power loss
I admit that the fix is probably quite obvious using the parts darts technique or best guess scenario, but I thought this particular job demonstrated the use of the WPS500 as an everyday aid to speed up the diagnostic process.

11/05/2015 Diesel Ford Power loss,
Diesel
Jaguar
E-type
1961

Unstable idle speed
The vehicle in question was a 3.8 E-type straight 6 cylinder. Our customers concern was unstable idle speed, reluctance to rev, and horrendous backfiring with hesitation at wide open throttle (WOT [the default position for E-type drivers]).

11/05/2015 Petrol Jaguar Poor acceleration,
Poor idle,
Petrol
Jeep
Compass
2007

Cylinder misfire
I had a customer's 2007 JEEP Compass , European Spec, fitted with the VW 2.0l TDi PD engine (code BLY). Unfortunately standard VAG software (e.g. VCDS) cannot communicate with this ECU (due to it being a JEEP).

11/05/2015 Diesel Jeep Engine misfire,
Diesel
VW
Golf
2004

Noise, Vibration and Harshness
A MK5 VW Golf 2.0 TDI with a distinct vibration throughout the cabin at a very specific road speed range of 67- 73 mph, presented a real nuisance at cruising speed. This problem resulted in the customer driving at 65 or 75 mph to avoid the vibration.

11/05/2015 Diesel VW Cabin vibrations,
NVH,
Diesel
DAF
XF95

EBS braking fault
The customer complained of an EBS braking fault which occurred intermittently. When the fault occurred then the EBS light would illuminate on the display and the EBS function would revert to conventional braking.

11/05/2015 Unspecified DAF ABS fault,
EBS fault,
Unspecified
Toyota
Hilux
2007

Non-starter
Bought at auction. When viewed it was a non-runner, at the actual auction it ran! Numerous warning lights flashing, engine start and stalling, severe engine rattle under brief running conditions and excessive smoke via the exhaust. So where do you start? It has to be the beginning.

11/05/2015 Diesel Toyota Engine stalling,
Engine vibrations,
Non-starter,
P0200,
P0340,
P0355,
Diesel
VW
Caddy
2007

Lack of power, poor cold start
If at first you don't succeed...you know the rest. This case study follows post- purchase rectification of a 2007 VW Caddy 1.9 TDI (Engine code BLS). The Caddy was purchased at auction during the summer with the knowledge that the vehicle was not running at its best, but was "running"!

11/05/2015 Diesel VW Poor acceleration,
Poor starting,
Diesel
Toyota
Celica
2001

Poor running
The case study below demonstrates how PicoScope fits within the diagnostic jigsaw when resolving seemingly complex issues. The analogy of a jigsaw fits well if we look at the essential pieces required for a successful diagnosis.

11/05/2015 Petrol Toyota P0172,
Poor acceleration,
Poor idle,
Petrol
BMW
545 E60
2003

Charging system communication error
Here is one vehicle that has been suffering from repeated breakdowns as a result of what proved to be overvoltage.

11/05/2015 Petrol BMW Non-starter,
Poor acceleration,
Petrol
Toyota

Loss of power P1251
The Pico Journey forms a typical yet simple example of how PicoScope sits alongside any scan tool on the road to a successful diagnosis.

06/07/2015 Unspecified Toyota MIL on,
P1251,
Power loss,
Unspecified
Maserati
Quattroporte
2010

NVH Cabin Vibration
The trouble with vibrations is that we all interpret them differently (which is why we should measure and not guess), but with this vehicle you could not deny a considerable vibration throughout the vehicle in a very specific engine speed range. Starting at 1450 rpm through to 1700 rpm the vibration was evident, with peak vibration occurring around 1600 rpm.

23/07/2015 Petrol Maserati Cabin vibrations,
Engine vibrations,
NVH,
P0200,
Petrol
Ford
Fiesta 1.3 16 V
2001

Misfire
The topic of this case study is not so much "How we managed to diagnose the fault in question" but more about the multiple options at our disposal when it comes to diagnosing component failure.

25/09/2015 Petrol Ford Engine misfire,
P0301,
Petrol
VW
Polo 1.2 3-Cyl
2003

Misleading fault codes
When it comes to diagnosis a cool head must be maintained when all around appears to be crumbling. Our relationship with the customer pays dividends during diagnosis where rapport is essential when things appear to go from bad to worse. It is very easy to jump to conclusions when the evidence gathered during diagnosis points to a particular component. It is at this stage we should take stock and step away to ponder before we commit to our diagnosis.

30/10/2015 Petrol VW P0106,
P0172,
Petrol
Renault
Clio
2009

Renault Clio Fuel Pressure problem
This 2009 (MK3) Renault Clio 1.5 dCi engine had a complaint just after starting where a strange noise occurred for a few seconds followed by the MIL illuminating and the engine entering recovery mode.

15/12/2015 Diesel Renault DF007,
DF885,
MIL on,
Diesel
Honda
CR-V
2007

Severe hesitation
During hard acceleration, the vehicle violently surges back and forth. When the accelerator pedal is released, the vehicle resumes normal driving performance. The symptom is evident regardless of engine temperature, and is present whenever the driver attempts hard acceleration (the symptom is permanent).

25/02/2016 Diesel Honda Engine surging,
Poor acceleration,
Diesel
BMW
120 M Sport (E87)
2006

Juddering at low speed
Driving at low speed the vehicle appears to judder, accompanied with a yellow warning light illuminated within the instrument panel. The symptom was evident every drive regardless of temperature and road condition, and had been evident for over a week.

29/06/2016 Diesel BMW ABS fault,
Diesel
Jaguar
X Type
2006

Jaguar X-type with severe power loss
Engine warning light became illuminated, accompanied with severe lack of power under acceleration after changing gear or when pulling away from rest (evident for approximately 3 weeks).

26/07/2016 Diesel Jaguar P0405,
P132A,
Power loss,
Diesel
Renault
Scenic
2010

Faulty Throttle Unit
Once a week the vehicle’s injection warning light illuminated and the vehicle entered limp home mode. Switching the engine on and off cleared the warning light and the vehicle seemed fine for another week.

21/02/2017 Petrol Renault Petrol
Subaru
Legacy SE
2005

Subaru with incorrect ABS operation
There is noise/vibration from under the bonnet when driving at low speed over speed humps, accompanied with the ABS warning light.

07/03/2017 Petrol Subaru ABS fault,
Engine misfire (intermittent),
Petrol
Toyota
GT86 – ZN6
2012

Engine non-start
The engine is a non-start after a major engine overhaul. Compressions and valve timing have been checked and are correct.

23/05/2017 Unspecified Toyota Cabin vibrations,
Non-starter with cranking,
Unspecified
Ford
Focus 1.6 (Duratec-16V)
2007

Ford Focus Engine overheating
The engine temperature gauge indicated hot with “steam” creeping from under the bonnet.

24/07/2017 Petrol Ford Engine overheating,
P0480,
Petrol
Mazda
3
2015

Communications fault
Ben Martins was recently presented with a 2015 Mazda 3 with all warning lights on the dash illuminated, accompanied with around 40 DTCs (diagnostic trouble codes).

22/08/2017 Diesel Mazda U0100,
U0131,
U0151,
U0155,
U0214,
U0415,
Diesel
Toyota
Auris

Hybrid battery cooling system
It goes without saying that Hybrids and electric vehicles (EVs) should be treated with caution when it comes to service, repair and of course, diagnostics. We should not be fearful of such technology, though, once we understand the safety procedures involved and the operation of the system we wish to diagnose.

19/09/2017 Hybrid Toyota Hybrid Warning Light,
P0A82,
Hybrid
Mazda
BT 50
2006

Camshaft code on Mazda
This is a story about the power of using a scope and how Northside Master Auto Tech went about to diagnose a problem on a 2006 Mazda BT 50 Diesel

20/09/2017 Diesel Mazda P0340,
Diesel
Rover
100
1996

Finding faulty engine mountings with the NVH Diagnostics Kit
My 1996 Rover 100 helped me get to grips with NVH. The first test I did was in the passenger compartment with the accelerometer on the inner seat rail. I was a bit surprised by the magnitude of the engine second-order (E2) peak, but, with no experience to fall back on, I asked Steve Smith at Pico for advice.

26/10/2017 Unspecified Rover EBS fault,
NVH,
Unspecified
Seat
Leon II
2007

EML On and Fault Code P0491
The vehicle in question belongs to a staff member here at the Pico Head Office. The driver informed us that that EML (Engine Management Light) had come on but that there was no loss of power, nor did anything else happen apart from the light coming on.

27/11/2017 Unspecified Seat P0491,
Unspecified
Scania
R480
2008

Scania R480 – Poor idle, misfire, smoke and fault codes
I was recently asked to take a look at a 12.3 litre HGV. With this particular lorry, a slight misfire was evident at idle, which became progressively worse over time. There were no warning lights on the dashboard, but a strong fuel smell along with smoke and a heavy diesel knock when it was started up from cold; all the characteristics of over-fuelling.

12/12/2017 Diesel Scania Engine misfire,
Diesel
Fiat
Kobelco E135

Fiat Kobelco E135 Excavator - Engine shutdown
According to the operator, the machine had always been a little temperamental, but it really started acting up four months ago. The engine would stop suddenly, while the machine was being operated!

22/01/2018 Diesel Fiat Engine stalling,
Power loss,
Diesel
Tesla
Roadster
2010

ABS and TC warning lights
Upon driving the vehicle at normal road speeds the ABS and traction control (TC) warning lights illuminated. The symptoms were present at every drive, regardless of temperature and road conditions, and had been present for over a week. The warning lights lit upon ignition on and remained on until the ignition was turned off again.

23/02/2018 Electric Tesla ABS fault,
Electric
Ford
B-max
2014

EcoBoost– MAF Sensor
The vehicle was a 2014 B-Max, 1.0L, 3-cylinder, turbocharged petrol engine. It had been brought in as the EML was on with the fault code P0102 Mass Air Flow MAF Circuit Low. I was asked to take look at this new type of air flow sensor that, for now, has only been seen on the Ford EcoBoost engine. The fact that it is a 4-wire type that has a 12 V supply from the same fuse that the fuel pump gets its supply from makes it intriguing.

26/03/2018 Petrol Ford P0102,
Petrol
Opel
Kadett
1991

NVH diagnosis of transmission screech
The vehicle had developed a very loud screeching noise, which sounded like a cross between a squealing drive belt and a loose stack of rapidly vibrating metallic plates. The car was powered by the original GM 16SV OHC transverse-mounted petrol engine and the THM125 automatic transmission and had covered a genuine 52k miles from new.

26/03/2018 Petrol Opel NVH,
Petrol
Mercedes
GL550
2014

2014 turbocharger boost
This vehicle came in with the engine malfunction indicator lamp (MIL) illuminated. Using our Xentry diagnostic scanner we found diagnostic trouble code (DTC) P029900 was stored in the engine control module (ECM). Our first step was to find out what condition was required to trigger this fault code.

01/05/2018 Petrol Mercedes Petrol
Land Rover
Range Rover Sport L320
2007

Brake Booster Failure
When applying the foot-brake, the brake pedal appears hard to press intermittently whereby the customer has to apply more effort in order to bring the vehicle to rest. Upon the next brake pedal use the feel of the brake pedal and the effort required to stop the vehicle returns to normal! The symptom had been very intermittent regardless of temperature/road condition and been evident for over two weeks.

06/06/2018 Diesel Land Rover Braking fault,
Diesel
JCB
JS220
2007

EGR valve failure
The customer reported that there was black smoke coming from the machine, and that when it is running and loaded to the maximum, the engine stalls.

04/07/2018 Diesel JCB EGR fault,
Engine stalling,
Diesel
Triumph
Bonneville 1200
2018

Triumph investigation
We were recently asked to assist with the development, set-up and ultimately the tuning of a rather unique motorcycle. The request turned out to be a fascinating adventure into Motorbikes!

31/08/2018 Petrol Triumph Petrol
New Flyer
60ft Articulated Bus
2001

Random misfire
This bus I worked on took a little time to figure out but was very interesting in the end result of what the fix was. The initial complaint on this bus was excessive black smoke on acceleration and the occasional random misfire. So the first thing I did was I checked for codes and no codes.

27/09/2018 Petrol New Flyer Black smoke,
Misfire,
Petrol
Audi
A6 Quattro S-Line
2013

Parking Brake Failure (EPB)
Questioning of the customer revealed that the electronic parking brake (EPB) on the vehicle occasionally failed to release after being engaged overnight. When the fault occurs, the vehicle can be driven without any brake binding or drag, suggesting the parking brake has released. The symptom had been very intermittent for over 12 months regardless of temperature or driving conditions.

24/10/2018 Diesel Audi EPB - Electronic Parking Brake,
U0417,
Diesel
Mazda
CX-3

No audio
When attempting to switch the radio on, by using the touch screen interface, the radio button is highlighted but the menu cannot be accessed. The same condition is met when trying to use the command wheel in the center console. No audio or output to any of the speakers including satnav, Bluetooth or voice recognition. Volume also doesn’t work and when adjusting settings for treble, bass, left and right or front and back, the selection can be made but it reverts to the original position after a couple of seconds.

19/12/2018 Petrol Mazda DAB Amplifier,
Petrol
Fiat
Ducato
2016

Turbo under-boost and air flow meter drift.
Do you need a scope to diagnose vehicles? Well, it is coming up to the end of 2018 and I’m thinking about all the diagnostic problems I have had this year. I wanted to share the biggest I was involved with (I was helping a dealership).

23/01/2019 Petrol Fiat Poor performance,
Petrol
Nissan
X-Trail
2008

Faulty piezo Injector
How to test and diagnose piezo injectors without having to send them away? I had the opportunity to try out some new testing methods when I was asked to take a look at a Nissan X-Trail with two fault codes that pointed to all four injectors.

19/02/2019 Diesel Nissan Cutting out,
P2146,
P2149,
Diesel
Hitachi
Zaxis 135

MCU failure
Once again, I find myself standing in a muddy building site. This time looking at a machine with a number of warning faults. The operator could no longer increase the engines RPM in order to move the machine off-site. The machine had 7169 hours on the clock and a 4 HK 5.2 l engine.

22/03/2019 Unspecified Hitachi Poor acceleration,
Unspecified
DAF
CF

Cutting out with no restart
It seems that a lot of the faults I come across these days are communication-based and this vehicle is no different. The complaint this time is: the vehicle suddenly cut out and then wouldn’t restart.

26/04/2019 Diesel DAF Cutting out,
Diesel
Chevrolet
Uplander
2007

Crank sensor gap
To make a long story short, $2,200 later and with a replaced crank sensor, new knock sensors, a tune up, new wires to the crank sensor to eliminate bad wiring faults, etc, it was still not fixed. I’ve been trying to work on my diagnostics skills, so my tech took it on for me to have a challenge to work on.

22/05/2019 Petrol Chevrolet Poor performance,
Poor starting,
Petrol
Toyota
Camry (import)
2013

Camshaft correlation error (Quad Cam engine)
I am sure many of us have experienced the limitation of only having four PicoScope channels while being deep in the battle of diagnosis. Diagnosis commands that all variables are kept to a minimum, and from my perspective, there have been numerous occasions when six channels would have been perfect. Luckily, we now have an 8-channel Automotive PicoScope, and it was incredibly useful in this case study.

27/06/2019 Petrol Toyota MIL on but no symptoms,
Petrol
DAF
CF75
2010

DAF rear steering fault
I was asked by a customer if I was interested in taking a look at problem dust cart. The owners, in the attempt to get a silver bullet fix, requested a part replacement based on limited diagnosis. The part was reluctantly replaced by our customer but, as you’ve probably already guessed, it didn’t fix the problem. We were determined to do it properly, to find the fault, prove it and then verify the fix with PicoScope.

29/07/2019 Diesel DAF Diesel
Chevrolet
Suburban
2009

Misfire and MIL concern
Mario Rojas has written this case study where he looks at a misfire and MIL concern on a Chevrolet Suburban.

20/08/2019 Petrol Chevrolet Engine misfire,
MIL on,
Petrol
Lexus
GS 300

Driveline vibration problem
My customer bought the car 6 months previously. During the initial test drive, he noticed a slight driveline vibration. The salesman told him it came from the tires. The car got four new tires matched with rims, balanced and road force tested. But the car still had a driveline vibration.

26/09/2019 Petrol Lexus Vibration,
Petrol
Mercedes Benz
Sprinter 906

Lack of power
This vehicle came in with a customer complaint of lack of power; customer’s own words, “feels like it has no boost” and the CEL was illuminated. Using the Xentry diagnostic tool we found two fault codes stored.We were not able to obtain any specific information on the criteria for setting these fault codes. We reviewed the freeze frame data and it was unhelpful at identifying the conditions that the fault was set under.

18/11/2019 Petrol Mercedes Benz Petrol
Kuboto Mini Digger
KX161-3ST (5 tonne)
2007

Lack of digging power
This isn’t the most in-depth diagnosis on this machine, but we used PicoScope to record each step of the diagnostic process to verify the fix.The machine I came to look at was relatively old with plenty of hours on it and it had had a bit of a tough life. The customer’s complaint about this machine was that it was down on digging power.

11/12/2019 Unspecified Kuboto Mini Digger Power loss,
Unspecified
Volvo
FMX V4 Euro 6
2016

Fuel Pressure Fault
I know there are a few of you out there that are interested in using the PicoScope on trucks so I thought I'd share my process in this case study. I have done a few of these now and Pico has definitely improved the accuracy and speed of the diagnosis.

17/01/2020 Diesel Volvo Poor performance,
Power loss,
Limp mode,
Engine system failure light,
Diesel
BMW
320D M Sport xDrive Touring
2013

Cabin vibration at motorway speeds
The customer reports that vibration can be felt through the vehicle at approximately 75 mph. The symptom has been present for over 2.5 years, and they have had numerous attempts to resolve the issue.

21/02/2020 Unspecified BMW NVH,
Unspecified
Hitachi
Zaxis 470

Lack of power - diagnostic process
Have you ever been in the position where a customer calls up to say ‘the machine is down on power and we think it’s the hydraulic pumps so can you replace them?’ You respond by saying ‘of course but wouldn’t you rather we look at it first?’ ‘No, just price it up, it needs to be fixed.’

16/03/2020 Unspecified Hitachi Unspecified
BMW
320D M Sport xDrive Touring (RH-Drive)
2013

Knocking noise from steering column
We look at a known and documented issue surrounding a knocking noise from the steering column area of a BMW that can be heard inside the cabin. The issue was solved at the Check for Technical Bulletins (Recalls & Campaigns...) stage of the diagnostic process. However, this is a great opportunity to demonstrate how to objectively locate intermittent knocking noises, which are time-consuming and potentially expensive to diagnose.

20/04/2020 Petrol BMW NVH,
Petrol
Manitou

A telehandler with a slow winch - part 1
We’re about to follow a journey where it, in total, took nearly a year to find the solution. I had a phone call about visiting a Manitou Telehandler. The customer reported that the winch accessory was slower than that of other machines. Several other people had already taken a look at this machine but my plan was to get a more detailed understanding of the fault with the PicoScope and hopefully be able to pinpoint the problem to the customer.

18/05/2020 Unspecified Manitou Unspecified
Manitou

A telehandler with a slow winch – part 2
We’re continuing the journey following Ben's work on the telehandler with the slow winch. Will they be able to find the problem?

18/06/2020 Unspecified Manitou Poor performance,
Power loss,
Unspecified
Renault
C460

Misfire
This one is a short case study, but it shows that with the right steps, you will find the task easier. The customer complained of poor performance and vibration which feels like a misfire. There were no warning lights on the dashboard.

17/07/2020 Unspecified Renault Misfire,
Unspecified
Renault
Zoe
2013

Warning message “STOP: Electric failure DANGER”
Technology is changing at a relentless pace, presenting challenges to technicians worldwide. For those who are not brand-specific, diagnosing anything and everything, these challenges are beyond consuming. The following case study is one such example. I would like to share the hurdles I had to be overcome when I attempted to diagnose a Renault Zoe with virtually zero product knowledge. Throw into the mix an “All Electric Drive Train” and you just know you are going to reach that point during the diagnosis where you ask yourself why.

19/08/2020 Electric Renault Electric
Renault
Kangoo
2014

Kangoo EV charging fault
With the growing number of EV vehicles on the road, it is tough keeping up with new technology. The increase of EVs has led to a number of the typical internal combustion engine issues being eliminated, with some manufacturers stating servicing is optional. All that aside, EVs are not without faults. In our previous case study, Steve took us through how important the 12V system is to an electrified vehicle. This time around, we will take a look at a Renault Kangoo with a charging issue and the hurdles that diagnosing this type of fault brings.

27/09/2020 Electric Renault Poor charging,
Electric
Mercedes
E300
2014

Warning lights and limp-home mode Part 1
In this ever-changing world, there is one constant in our trade: cars will break down. As we try to build our knowledge and the level of complexity increases, there are always things that can trip you up. This particular case was no exception, with twists and turns all the way!

18/11/2020 Hybrid Mercedes Hybrid
Mercedes
E300
2014

Warning lights and limp-home mode Part 2
This is part 2 in Ben's case study about the Mercedes E300 Hybrid with multiple warning lights.

15/12/2020 Hybrid Mercedes Poor performance,
Limp mode,
Hybrid
Fiat
500
2011

Engine warning light illuminated: Engine misfires from cold
While the electric vehicle revolution marches relentlessly on, fuel-efficient internal combustion engines will have a place in future powertrains for years to come, either as the sole power source or a range extender for electric drivetrains. The challenge of squeezing every last drop of energy out of each gallon of fuel pushes both engineering and engine management to another level.

19/01/2021 Petrol Fiat Petrol
BMW
i3
2016

Does not switch to Ready mode and drivetrain error message displayed
While the future may be Electric, and technology marches on at a relentless pace, the following case study highlights a typical fault we have seen on numerous vehicles for many years. It is as relevant today as it was all those years ago.

23/02/2021 Electric BMW Non-starter,
Electric
Honda
Civic FK2 (8th generation)
2007

Engine rattle at idle speed
While the future may be “Electric” the internal combustion engine (ICE) has many years left before it disappears forever. However, I am certain that it never will. Looking at the current legislation, 2030 will see conventional petrol and diesel cars/vans banned from sale with an extension to plug-in hybrids until 2035. (Used cars will be unaffected by the ban). If we do the maths on the above, the ICE will continue to be present in various vehicles up to 2035 along with a multitude of vehicles going back to 1886. Needless to say, that is a lot of engines with potential for diagnosis and failure. The following case study looks at the application of PicoScope and the NVH software when tackling a typical engine noise and consequential failure.

23/03/2021 Petrol Honda Non-starter,
NVH,
Petrol
Komatsu
138US
2016

Engine hunting under load
You’d have thought that when faced with construction equipment, the smaller the engine the easier it would be to work on. That couldn’t be further from the truth! A smaller machine typically means it’s more difficult to work on. This little 14T Komatsu was no exception as we were to discover.

21/04/2021 Unspecified Komatsu Unspecified
Vauxhall
Vectra Auto
2005

Intermittent non-start
The challenges we face when doing a diagnosis do not only require investment in test equipment, training and hours of ongoing study. We also need to manage the diagnostic task at hand. The following case study is one such example, where the costs of the diagnosis and the parts required exceed the value of the car, yet the drive and ambition to discover “what was wrong” dominated over our better judgment.

25/05/2021 Petrol Vauxhall Non-starter,
Non-starter with cranking,
Petrol
Honda
Civic
2007

Severe vibration under acceleration
NVH diagnostics requires a methodical approach and evaluation of test results to reach a conclusion that is satisfactory for all parties involved. The case study below describes the rapid identification of a customer’s complaint of vibration and how using multiple sensors (either microphones or accelerometers) become invaluable in locating the source of the problem.

23/06/2021 Petrol Honda Cabin vibrations,
Vibration,
Petrol
Volvo
XC90
2003

Non-intrusive engine evaluation
A recent visit with a Volvo XC90 with a permanent misfire problem provided a great opportunity for a non-intrusive engine condition evaluation. How we tackle such symptoms of misfire is predominately governed by experience, probability and accessibility. By doing a non-intrusive engine evaluation, you can provide a cost-effective initial diagnosis and deliver conclusive evidence on how to proceed with rectification.

21/07/2021 Petrol Volvo Engine misfire,
Petrol
Case
821F
2015

Wheel loader with loss of communication
A Case wheel loader with 13 127 hours on the clock and a communication problem. Ben went to the seafront to help diagnose the issues on this machine. It had been suffering from an intermittent problem for weeks with no obvious way to reproduce the fault.

23/08/2021 Diesel Case CAN Bus error,
Diesel
Audi
Q7 e-tron
2017

Fails to charge via plug-in charger
While electric vehicles appear to be the future, plug-in hybrid vehicles seem to be the order of the day when it comes to the best of both worlds. Such vehicles can drive on pure electricity, meeting the current low emission regulations for cities, yet, with old faithful on-board – the internal combustion engine, we can take advantage of seamless mileage without suffering range anxiety. (What’s not to like?) Both power sources have their distinct pros and cons but somehow, when you combine the two, you have a formidable vehicle that ticks almost every box. The following case study focuses on the plug-in high-voltage (HV) charging system of a hybrid vehicle and the challenges encountered along the way.

20/10/2021 Hybrid Audi Poor charging,
Hybrid
Komatsu
PC210 LC

Komatsu PC210 LC AdBlue fault
The following adventure started with a back story where the machine had been looked at previously and parts had been replaced. I had a quick chat with the operator who reported that after the second time it was looked at it worked for around four hours before moving to a level 4 warning where the engine was derated and performance from the machine was seriously downgraded to the point where only a high idle engine speed was possible. The other rather annoying part of a level 4 warning is a constant sounding alarm as soon as the ignition was switched on, with no way of turning it off till the fault was fixed.

11/11/2021 Diesel Komatsu Diesel
Gleaner Combine Harvester

Guest case study
This guest case study from Tony Nott, of Michaels Moama Australia, investigates the diagnostic process on a Gleaner Combine Harvester.

27/01/2022 Petrol Gleaner Combine Harvester Petrol


Guest case study: Aircon malfunction, no cold air, no DTC.
This guest case study from Rfmotors1, investigates an aircon malfunction.

23/03/2022 Unspecified Unspecified

Pierce Aerial Ladder

Guest case study: Pierce Aerial Ladder
Edward Boers was kind enough to share his experience of working on a Pierce Aerial Ladder.

24/03/2022 Unspecified Unspecified
DAF
CF

DAF DEF warnings
DAF CF shows multiple warning lights and alarms on the dashboard.

28/06/2022 Petrol DAF Petrol