One month ago I got a message from a garage owner, him having my phone number from another garage. It was about an Opel Zafira B, 2005 build year, imported car from Germany.
The car problem was described as: if engine is warm, it will not crank, all dashboard lamps will be on. Because he is 1.5h away from me, I asked for a fault codes list. He sent me the list, standing out were canbus communication faults and engine ecu replace faultcode. Also a nice picture with the engine ecu. Someone has been busy there.
We've basically agreed that I should bring an replacement ecu. The distance to the garage was too big to worth two round trips. Today I went there and this is what I found.
Because I learned it the hard way a previous time, first thing to do was to connect a power supply to the dead battery, extract the security code out of the engine ecu. It was a smart move, as you will read below. Second, it came coffee with sugar. Third, fault codes reading and here comes the fun.
THE list:
Key on, engine off, engine lamp blinking.
UEC=Underhood electrical center
CIM=Column Integrated Module
EHU=Entertainment Head Unit
EHPS=Electrohydraulic Power Steering
AHL/AFL=Auto Headlamps Leveling / Adaptive Forward Lighting
IPC=Instrument Panel
DIS=Info Display
Engine
P1614 50 Wrong transponder key Present
U0140 70 canbus no communication with cim Not Present
U0121 70 canbus no communication with abs/tc Not Present
U0009 70 canbus node no communication Not Present
P1616 00 CIM wrong environment identifier Not Present
P1613 00 Immo no or wrong signal Not Present
P0601 30 Replace Electronic Control Unit ECU Not Present
P0501 F0 vehicle speed sensor malfunction Not Present
P0650 70 canbus failure no can message Not Present
UEC
B2530 00 Front fog light circuit low voltage Present
CIM
U2105 00 canbus no communication with ECM Not Present
B3055 00 Transponder key problem Not Present
EHU
U2206 00 canbus no communication with DIS Not Present
EHPS
U2105 00 canbus no communication with ECM Not Present
AHL/AFL
U2105 00 canbus no communication with ECM Not Present
U2139 00 canbus no communication with CIM Not Present
U2143 00 canbus no communication with SAS Not Present
ABS/TC
U2105 00 canbus no communication with ECM Not Present
C0800 03 System voltage low voltage Not Present
IPC
P0460 71 fuel level sensor circuit range / performance Not Present
P0115 71 engine coolant temperature signal range performance Not Present
P0654 71 engine speed signal range / performance Not Present
P0500 71 vehicle speed signal range / performance Not Present
P0550 71 mileage circuit range / performance Not Present
DIS
U2139 71 invalid data from CIM Not Present
I had 3 keys with the car and it turned out that one key was defect. So I could of start the engine with the other 2. At that moment, I decided not to replace the ecu just yet, weather was fine, and I took my time. What if the ecu is not the problem? While I looked into the fault codes, trying to figure out what is going on, I just left the key in, contact on.
Canbus diagram sorted and this is how it should be connected for high speed canbus:
It was perfectly viable that, with a faulty UEC, all modules would not connect to Engine ecu. And it is known for these cars Zafira B / Astra H to have connection problems at the UEC (water ingress). What if the previous repair focused on ecu and forgot (did not knew) about the UEC problem? Questions, questions.
Not a moment sooner, I heard the throttle body re calibrating itself. I was already with key on for ... something like 15-20 minutes?
And the dancing lights started in the dashboard.
Even better, this car is screaming for attention:
Another scan, and all not present canbus faults, were Present again. This is actually good, I got the problem in front of me, just there to be found. Key stays on where it is. No one is allowed to touch that.
But I cannot connect to ABS, engine ECU does not respond, AHL is just not there on the bus.
Do you think what I think? Its time for the canbus break-out box. All plugged in and I got this nice picture. Sorry I did not save the pico file, I was fascinated.
The beginning of the message does not look that bad actually, but what is that on 120, 270 and 420 us? And looks like same data. Something tries to speak on the bus but it does speak foreign language to the bus. Its like me speaking when I'm drunk.
I don't know about you, but I had enough of it and went to remove the engine ecu chassis plug. Key is still on.
And there was silence in the dashboard. Kind of, but fully acceptable to the moment.
Canbus looks suddenly much better:
But hey, UEC was not yet excluded, right? Bad connections can still do these things. So I scoped the canbus straight at the engine ecu plug, still normal data according to me. UEC is not the culprit here.
Did you noticed the extra oscillations at the beginning of voltage rising / lowering? That is caused by a can network of 120 ohms instead of 60 ohms equivalent (ecu is out of the loop now).
I've tried also to measure can lines resistance but I would be ashamed to tell you how I did it. There was no ground fault, at least.
Finally key off, another ecu placed, all programmed, fault codes deleted. I've let again key on for a while but nothing else strange happened. Engine started first try and there I was with a happy owner.
Now, why exactly this ecu failed, I do not know. What I did found out was that the low speed for cooling fan did not work, it should start at 108 degrees C, high speed started at 112 degrees C. This ecu was running too hot I think.
liviu2004 wrote:
Now, why exactly this ecu failed, I do not know.......
I think they fail because they can, I had one a while ago, non start as it was looking for auto transmission control module on the network that it could not find as it was factory fitted with 5 speed manual and never been played with, all coding was correct.
Replacement ecu also sorted that
Another way to diagnose these Hybrid ECU's failing is to grab the multiplug(s) and stress them up and down - you can make the fault codes come and go at your pleasure.
I think they fail because they can,
Without doubt it is the ultrasonic bonding between the Connector Plug and the Circuit board that fails every time. Not helped by the fact that they are mounted to a constantly vibrating surface that can go from -20 degrees C to +100 in minutes. Similar to the Bosch VP44 Pumps where the vibrations and heat shake the transistor in the corner to death.
STC wrote:Another way to diagnose these Hybrid ECU's failing is to grab the multiplug(s) and stress them up and down - you can make the fault codes come and go at your pleasure.
Without doubt it is the ultrasonic bonding between the Connector Plug and the Circuit board that fails every time........................................................................................
I wouldnt say every time, yes seen a few, this one today, Astra with Delphi 12214860 ecu, bolted to engine, had the normal codes, again new ecu fitted and programmed in sorted it.
I opened the old one and painstakingly checked every ultrasonic bond with a very fine tipped pick and they was all good, maybe component failure