A to Z of PicoScope

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Connection to a vehicle component is key when diagnosing a fault. Often, finding a way of connecting your generic tool of choice to the particular vehicle you have in the workshop is not always straightforward.

The M18 is often used once a spark plug has been removed from the engine. The M18 adaptor is then used in order to carry out a compression test on a range of petrol (gasoline) engines with the WPS500X.

More information on Adaptors for WPS500X - M18 >>

Pico has added two more adaptors and a connector hose to its selection of accessories for the WPS500X: The Right-angle Rectus-21 pressure adaptor, the Male-to-male Rectus-21 pressure adaptor and the Short hose with a female-to-female coupler (Rectus-21).

More information on Adaptors for WPS500X and Sight block >>

Alarms are actions that can be set up to execute when selected events occur, with your PicoScope providing automatic functions.

More information on Alarms >>

Also called DC offset. This valuable feature can give you back the vertical resolution that would otherwise be lost when measuring small signals.

More information on Analog offset >>


An attenuator is an electronic device that reduces the power of a signal without distorting its waveform.

The Pico Technology TA197 is a passive 10:1 attenuator. This means that a 10 V signal at its input will appear as a 1 V signal on the output. Attach one to a PicoScope and you can measure signals up to ±400 V without damaging the scope.

>> More information on the TA197


When you press the "lightning" button on the Setup toolbar, PicoScope searches for a signal on one of the enabled input channels, then sets up the timebase and signal range to display the signal correctly.

More information on Auto setup >>


If you have added a few input channels, maybe some reference channels and have enabled math channels, it can take time to move them around and scale them so that they are all clearly visible. Auto-Arrange will automatically position and scale the traces so that none of them overlaps.

More information on Auto-arrange >>


Did you know that your PicoScope also can operate as a highly accurate and efficient battery and charging circuit tester? This allows you to test your customers' vehicles without the need for dedicated, expensive test tools.

More information on Battery, starter and alternator test >>

At Pico, we work with many different types of vehicles in different markets. Our connection with Vehicle manufacturers and testing of new systems for software builds, give us great access to new vehicles. Most manufacturers use large breakout boxes, which can be very expensive and time-consuming to connect on the vehicles.

Check out our breakout leads and breakout lead kits here.

More information on Breakout leads kits >>


The true value of a breakout box (BOB) can never be truly appreciated until you have used such a device in the heat of diagnosing. This piece, focuses on our 16-pin CAN Test Box, which connects directly to the 16-pin (OBD) diagnostic connector mandated on literally millions of vehicles all over the world. At first glance, the need for a breakout box may not be apparent as you can probe the OBD connector terminals quite easily in order to measure the values present on each of the 16 pins. However, the 16-pin BOB comes into its own when we start looking at speed, accuracy and security, which is essential during any diagnosis.

More information on 16-pin CAN Test Box >>

CAN Decoder

CAN and CAN FD bus decoding – overview

CAN bus (Controller Area Network) is a serial data standard originally developed in the 1980s by Robert Bosch GmbH for use in automotive applications. Today it is also widely used in industrial process control and aerospace applications.

It allows microcontrollers and electronic devices to communicate with each other without using a host computer and provides fast and reliable data transfer in electrically noisy environments at low cost and with minimal wiring.

CAN employs differential signaling to provide a high level of immunity to electrical noise.

PicoScope software allows many frames of CAN and CAN FD (Flexible Data-rate) data to be fully decoded both in a table format and in a colour-keyed trace, time aligned with the data signal.

More information on CAN & CAN FD - serial protocol decoding >>


You can use Channel labels to describe the measurements on your scope channels. You can select from a list of over 250 common automotive measurements or create your own custom labels.

More information on Channel labels >>

The COP probe is the fastest way to check coil-on-plug ignition coils and spark plugs, to:

  • find misfires fast
  • display scope patterns of the secondary ignition, which is faster than scoping the primary ignition

It can also:

  • work on all automotive scopes capable of displaying ignition patterns
  • be used to investigate injectors and other inductive actuators
  • allow for easier access to hard-to-reach components

The coil–on–plug and signal probe works with most COP systems; it requires no special adaptors, no foil strips, and no batteries. It eliminates the need for back-probing: to use the probe simply press the probe against the coil.

Check out the COP probe here.

More information on Coil on Plug (COP) and Signal Probe >>

Your PicoScope 7 Automotive software is available for MS Windows, macOS and Linux PC-based operating systems and works with all previous generations of PicoScope Automotive oscilloscopes. Furthermore, PicoScope 7 Automotive data files can be shared, saved and loaded across all the supported operating systems.

More information on Compatibility >>

Check for mechanical issues in seconds: Simply clip the test leads to the battery and crank the engine. The relative compression of each cylinder is shown in an easy-to-understand bar graph format.

To show absolute compression, add an optional pressure transducer to one cylinder, and the software will calculate the pressure for all cylinders in bar or PSI.

More information on Compression test >>


ConnectDetect® indicates whether you have good connections between your test leads and the circuits.

ConnectDetect® is only available on PicoScope 4x25 and 4x25A Automotive oscilloscopes.

More information on ConnectDetect® >>

Pico’s range of current clamps is a group of accessories that suits multiple applications. They can be used to confirm that a component under test is connected to a complete circuit and, more importantly, that an event took place. The event may be the operation of any component that consumes current, such as solenoids, injectors, motors, actuators, pumps, volume or pressure control valves, and relays. All this information can be obtained by simply placing a component cable in the jaws of a current clamp.

More information on Current clamps >>


You can use Custom probes to transform and scale your measurements to have different values, units or ranges. 

 For example, you can:

  • Convert the output of a non-PicoScope probe or measurement device that doesn’t already have the necessary probe settings built-in to PicoScope.
  • Transform the measured output of a vehicle sensor so you can compare it with that reported on a scan tool connected to the on-board diagnostic system.
  • Create a new probe based on the rescaled output of an existing probe.

More information on Custom probes >>

Check for misfires, and check if each cylinder is contributing the same amount of power, with the cylinder balance test.

Simply connect channel A of the PicoScope to the vehicle battery and start the engine. The software detects changes in engine speed as each cylinder fires. An easy-to-understand bar graph display shows the relative power output from each cylinder.

Please note: this test will not work correctly on certain vehicles that disable cylinders for emissions control reasons, or on low-compression engines with 8 or more cylinders.

More information on Cylinder balance / misfire detection >>

With the introduction of the new 4x25A Automotive PicoScope comes a number of PicoBNC+ accessories. These take advantage of the new and unique connection type on the scope and offer improved performance over existing BNC probes.

One such accessory is the new PicoBNC+ 60 A current clamp (TA473), which can boast of superior resolution during low-current measurements, such as parasitic drain.

More information on PicoBNC+ 60 A AC/DC current clamp test >>


PicoScope Automotive oscilloscopes have waveform buffer sizes of up to 250 million samples – many times larger than competing scopes. Most other scopes with large buffers slow down when trying to use a lot of memory, so you have to manually adjust the buffer size to suit each application. You do not have to worry about this with PicoScope deep-memory scopes, as hardware acceleration ensures you can always use deep memory while displaying at full speed.

More information on Deep memory oscilloscopes >>

We have been using the WPS500X pressure transducer kit for eight years now, and we are always thinking about new accessories to use and tests to perform to gain information about an engine’s efficiency and performance. In the Diesel glow plug adaptor kit, we have included gasoline compression adaptors for various sizes of spark plugs and hoses. This makes you able to connect to vacuum and exhaust relevant sensors and systems. 

See the product page for the kit here.

More information on Diesel glow plug adaptor kit >>

Many automotive oscilloscopes still use an analog trigger system based on comparators. This causes time and amplitude errors that cannot always be calibrated out, and that often limits the trigger sensitivity at high bandwidths.

More information on Digital triggers >>

PicoScope software is designed to make the best use of your display area, maximizing the waveform size. This makes sure that you see as much information as possible, in outstanding detail. With a PC or laptop, the viewing area is bigger and in higher resolution than any handheld tool, allowing you to make use of PicoScope’s flexible split-screen capability. As the example shows, PicoScope software can show multiple waveforms, each with its own individual zoom, pan, and filter settings for ultimate flexibility.

More information on Display >>


Electric vehicles also require diagnosis and repair, but there are a few major differences that affect the technician's work. Although the powertrain is completely different, so you certainly don’t need to worry about ignition timing, there are a host of convenience, safety, entertainment, handling and interior functions that are just the same as on any other advanced vehicle.

PicoScope is set up to provide rapid analysis of body and chassis systems, including motor and lighting currents.

PicoScope is the tool chosen by Tesla Motors and some of the world’s other leading developers and manufacturers of electric and hybrid vehicles. They know the benefits PicoScope can deliver on customer satisfaction and cost, through improved "fix it right first time" results.

More information on Electric & hybrid vehicles >>


Automotive PicoScopes are fast enough to display FlexRay signals accurately. FlexRay is a vehicle data bus standard used in active suspension systems. Its high speed means that the signal quality is critical, and only a fast scope can reveal problems like reflections and ringing.

We recommend using the 100 MHz Oscilloscope Probe for connecting to FlexRay signals, to make sure you have minimal distortion. This probe is included in PicoScope Advanced Diagnostic Kits.

More information on FlexRay >>


Full screen expands the graph area of your chosen view so it fills the whole screen.

More information on Full screen >>

With today’s complex vehicle systems and accessibility to components seemingly more restrictive, using the fuse box to access these circuits can be an easy option (once you locate the correct fuse for the circuit you want to test). Refer to technical data for the location of your vehicle's fuse boxes (usually one is found within the engine bay, and one can usually be found in one or other of the front footwell areas. Newer vehicles are also known to have a fuse box located in the luggage area. Once you have located the fuse of the component required for testing, remove the fuse and place it into the correct style fuse extension. Plug the fuse extension into the fuse's original location.

Click here to see our products page or read

More information on Fuse extensions and current clamps >>



Guided tests provide you with information and settings that support you through your diagnostic test process. For example, they:

  • Set up the scope for you
  • Show you the required probes and connections
  • Describe how to perform the test
  • Provide example waveforms
  • Detail the typical waveform characteristics and what they mean
  • Describe how the system and components should work
  • Outline related failure modes and the symptoms they can cause
  • List related DTCs

More information on Guided tests >>


Hall effect

The Hall effect sensor is commonly used in camshaft and crankshaft position sensors, but can also be found in other applications, such as ABS sensors.

PicoScope displays the Hall voltage pulses as a square wave, thereby reproducing the signals received by the camshaft and crankshaft position sensors.

More information on Hall effect >>


PicoScope has a wealth of features included in the design from the start. This way it can better equip you in the fight against intermittent problems. 

More information on Intermittent faults >>


Don’t know your BCM from your ECM, or your CAN from your LIN? You’re not alone. Click on this link to see the list of some of the popular abbreviations that are used in automotive diagnostics: https://www.picoauto.com/library/jargon-buster

JCASE is a cartridge-style fuse with a female terminal design, providing both increased time delay and low voltage drop to protect high-current circuits and handle inrush currents.

More information on JCASE fuse >>


PicoScope software provides a set of default and advanced keyboard shortcuts (called a map) that provide access to common functions. You can create your own maps, and can also import/export maps for loading onto another PC in case you use your PicoScope with more than one computer.

More information on Keyboard shortcuts >>

Focus piece: Keyless entry signal carrier detector

Here at Pico Technology, we are always looking to solve problems with modern vehicle system as manufacturers change the way their car works. Keyless entry has been around for years and now we finally have a way of testing the sensors.

You can find the keyless entry signal carrier detector here.

More information on Keyless entry signal carrier detector >>


LIN (Local Interconnect Network) is a serial protocol used in automotive electronics to allow microcontrollers to communicate with low-speed peripherals. The standard was defined by the LIN Consortium, a group of five vehicle manufacturers. It uses a single wire pair with a master-slave topology, offering lower cost, reliability and data rates than CAN – hence its use in non-critical, low-speed applications.

More information on LIN >>


A lowpass filter reduces measurement noise occurring at frequencies above some user-specified value (the cutoff frequency).

A separate lowpass filter can be applied to each of your channels so the noise present on each can be filtered differently, or not at all.

The lowpass filters are applied to each complete waveform buffer after the measurements have been captured; you will not see their effects until the buffer is full

More information on Low pass filter >>



You can use Math channels to create alternative versions of your measurements and gain more insight into your test results.

You are free to create as many Math channels as you require and each one can be the result of one or more operations performed on one or more of your original measurements.

Math channels waveforms are created after each measurement buffer has filled; you will not see them until after the buffer is full.

Example Math channels operations are:

  • Invert a measurement.
  • Add, subtract, multiply or divide measurements.
  • Transform a measurement into a running estimate of its frequency.
  • Calculate a running estimate of a measurement’s positive or negative duty cycle.
  • Convert an analog or digital Crankshaft Position (CKP) sensor output measurement to a running estimate of crank speed (RPM).
  • Filter your measurements using highpass, lowpass, bandstop and bandpass filters.
  • Apply many other scientific and trigonometric functions to your measurements.

More information on Math channels >>


PicoScope Measurements can calculate the values of many different, but commonly observed, waveform characteristics or features.

You can add multiple Measurements to each measurement channel and their values are calculated and displayed when the data has been captured.

Example Measurements are:

  • Minimum, maximum, peak to peak, mean and RMS amplitudes.
  • Frequency and cycle time.
  • Negative and positive duty cycle.
  • Edge counts, including rising and falling edges.
  • Pulse widths, including high and low pulses.
  • Rise and fall times and rates.

More information on Measurements >>

The best way to diagnose an intermittent fault is often to set up the scope to measure from several components and wait for the fault to occur. For an intermittent misfire, you might want to capture several minutes of cam, crank, ignition and injector waveforms. These types of tests require an oscilloscope with a "deep" memory buffer so that you can capture for long periods of time and then zoom in without any gaps or loss of detail.

With PicoScope, you can collect 250 MILLION samples, more than any other automotive oscilloscope. Our advanced "always-on" memory technology uses hardware acceleration to make sure that the processing of large amounts of data does not slow the oscilloscope down even when you are using a slower or older PC.

More information on Memory buffer >>


Noise and vibration kit (optional)

Improvements in damping and sound insulation in modern vehicles mean that vibrations and noise that would previously be ignored (by turning up the radio) are now diagnostic headaches. Many hours can be spent, and many parts swapped, in tracking down customer complaints.

The NVH kit works with your PicoScope to quickly identify the source of the problem. If the customer complaint is noise, use the microphone; if it’s a vibration, use the accelerometer. Sophisticated software quickly pinpoints the source of the problem.

The kit can be enhanced with accessories to also allow on-vehicle driveline balancing.

More information on the NVH kit >>




With a simple connection to the battery, the PicoDiagnostics software quickly performs the following tests:

  • Compression test. Crank the engine to quickly display the relative compression of each cylinder.
  • Cylinder balance / misfire detect. Compares the power output of each cylinder and highlights misfires.
  • Battery test. Displays CCA, measures state of charge and voltage drop during starting. Gives an overall Pass or Fail.
  • Starter motor test.  Checks starter coil resistance and voltage drop across cables.
  • Alternator test.  Measures charging voltage and current. Checks for excessive diode ripple.

More information on PicoDiagnostics >>


PicoScope 6 Automotive is the previous major version of our software for PicoScope Automotive oscilloscopes.

We now recommend using PicoScope 7 Automotive as, unlike PicoScope 6 Automotive, it will continue to receive regular new features, updates and bug fixes.

More information on PicoScope 6 Automotive >>


PicoScope 7 Automotive is the latest major version of our software for PicoScope Automotive oscilloscopes.

The software receives regular updates, accessible within the software, which provide new and updated features and bug fixes.

More information on PicoScope 7 Automotive >>

Do you know that Pico has a variety of different Premium test leads to use with your scope?

You can find our test leads here.

More information on Premium test leads and USB cables >>



Rotation rulers

PicoScope can draw Rotation Rulers on a waveform to indicate rotation angles of the crankshaft or camshaft. This feature is particularly useful for analyzing compression waveforms on a four-stroke engine.

  1. Capture your waveform (or load a previously captured one from disk).
  2. Drag the green dot (the rotation ruler handle) to the start of your waveform. This represents 0°.
  3. Drag the second green dot to the end of your waveform. This will usually be 720° for a four-stroke engine.
  4. Set the Partitions control to 4 and PicoScope will then automatically divide the waveform into four equal partitions, representing the four strokes of the engine cycle.
  5. PicoScope will display measurements in rotation angles (or any other rotation units that you choose.)

Time rulers

The time rulers measure time on a scope view. In the scope view, the small white squares on the time axis are the time ruler handles. When you drag these to the right from the bottom left corner, vertical dashed lines called time rulers appear.

At the same time the Ruler legend will appear. This shows the position of any time rulers that are in use. If there are two time rulers, it will also display the difference between them. Clicking the Close button on the ruler legend deletes all the rulers.



Samples are best explained when we think back to the days of creating a line graph on graph paper. You would take your data, and count along the x and y axis in order to mark a point, before moving on and making another, and another and another. You would then draw lines between these points to make your line graph.

These points are called samples (the lines you drew are how the oscilloscope draws the waveform between these samples).

Sampling rate

Leading on from our Samples information, sampling rate is simply how many samples will be taken per second. This setting is important when you think about the amount of data you wish to collect, and over what time period.

For a slowly changing signal requiring a longer recording time, use a low sampling rate. For a fast-changing signal over a short time period, use a high sampling rate.

The sampling rate is controlled by the Number of Samples setting in the PicoScope software. Here you tell the software how many samples you wish to collect across your capture. The actual sampling rate (X S/s) can be seen in the Properties panel (Views > View Properties).

When choosing a sampling rate, you must consider the timebase you are capturing over and the memory of your scope (our latest automotive scopes all come with a 250 million sample memory).

Serial protocols are on every modern vehicle, and increasingly there will be multiple serial data buses on every vehicle. Some of those will be present on the J1962 (often known as OBD, EOBD or simply 16-pin) connector for communication with serial diagnostic (or scan) tools. Many will be private and vital for the internal operation of the vehicle and essential systems.

PicoScope includes a special feature for decoding the serial protocols, together with standard voltage based testing to reveal problems like noise, poor levels, unbalanced differential signals and a host of intermittent problems. 

The common protocols found on modern vehicles are CAN, LIN and FlexRay, with the impending deployment of a new SENT protocol that provides digital data directly from sensors to ECUs.

PicoScope includes as standard decoding of all the above protocols and can reveal timing, bus contention and bus hogging by misbehaving ECUs. When the car is on the coverage list, but your serial diagnostic tool cannot even talk to it, have your PicoScope handy to check that all is as it should be.

The introduction of the Pico Sight Block this January opens up another level of diagnostic capability to the WPS500X. This accessory is extremely useful when you are looking for air in low-pressure diesel systems.

The Sight block is now available from Pico in the Sight block kit (PQ071). The kit comes with a stop valve for testing a negative pressure fuel pump under load and 3 sets of hose barbs for connecting to different size fuel hoses.

Click here to view the kit.

More information on Sight block kit >>



To select your desired timebase simply click on the Collection Time drop-down and select it (here we will use 20 ms/div).

The waveform capture area is split into 10 horizontal divisions now each with a value of 20 ms, meaning your total waveform capture time (timebase) is 200 ms.

20 ms/div is chosen as the general timebase setting to enable the scope to capture all events that take place during a 4 stroke cycle on one screen. This will ensure you miss nothing from injection to ignition events. Two valuable points to remember here are:  The four stroke cycle takes 150 ms to complete at 800 rpm and 1 second is equal to 1000 milliseconds.

To view more detail of a single event, reduce the timebase. To view more events with less detail, increase the timebase.


PicoScope is easy to use, but not everyone uses it all day and every day. To help both new users, and as a reminder for experienced technicians, Pico offers a wide range of training materials and training partners.

Training manuals, videos and other resources are available in our library (just select the library on the top level tabs).

In the training section you will also see details about Pico trainers in various markets. Any of our distributors can provide (or arrange) training, so please also contact them directly.

Visit our documents section, or view the case studies for even more heplful information and tips.

If you have any problems, please email support@picotech.com


A trigger ensures that the scope captures the waveform at the right time and keeps the waveform in a stable position on your screen. PicoScope usually sets up the trigger automatically once activated, but you can adjust the settings and the trigger mode in order to capture those unusual waveforms you might otherwise miss.


By Phil Rutt

The Ultrasonic parking sensor detector.

This 2-meter long lead with a detector is created to give technicians a way to prove the correct operation of each of the ultrasonic parking sensors in turn, by using PicoScope to show the strength of the signal from a given sensor.

More information on Ultrasonic Parking sensor detector >>

Many oscilloscopes can appear to have adequate specifications on paper, and it easier to polish a website description than it is to design a great scope from the ground up.

An key specification that is often omitted by some manufacturers is the waveform update rate, expressed as waveforms per second (wfms/s). This indicates how quickly an oscilloscope acquires waveforms.

PicoScope Automotive Oscilloscopes use deep memory and hardware acceleration to achieve over 100,000 wfms/s to better capture signal behavior and dramatically increase the ability of the oscilloscope to quickly capture intermittent problems such as jitter, runt pulses and glitches – problems that you may not even know exist when using an inferior product.

USB 3.0 for power, speed and simplicity

As with our previous generations of PicoScope oscilloscopes, no external power supply is required and there are no batteries to go flat, just a simple reliable connection to the USB port.

The PicoScope 4225 and 4425 have the latest SuperSpeed USB 3.0 port to interface to your PC. Don't worry if your PC only has USB 2.0 ports – the PicoScopes are fully compatible with these too. If you have USB 3.0 on your PC you will notice slightly faster screen update rates, faster file saving and USB streaming. As more of our customers move to PCs with USB 3.0, free software updates will ensure that you get the full benefits available from the new standard.

Our unique fast USB streaming allows continuous gap-free data to be collected straight to PC memory. This makes features like our cylinder balance, battery test and (optional) NVH tests possible. It also allows the oscilloscope to display live, real-time data without waiting for the screen to refresh.


Vibration is any oscillation (regular movement) that is felt or seen by the vehicle occupants. Vibrations have low frequencies, below 200 Hz.

The PicoDiagnostics NVH System analyzes and diagnoses problems with Noise, Vibration & Harshness (NVH) that can be very difficult to isolate without specific tools.

Vibrations can be subjective, but the Pico NVH system provides objective results and can provide you with customer reports for 'before' and 'after' any fixes.


The WPS500X features an extremely fast, 100 µs, response time from 0% to 90% of full scale, and sensitivity down to about 0.07 psi (5 mbar). This provides you with an accurate representation of rapidly changing signals that span a broad pressure range.

Use the WPS500X with PicoScope to have a detailed insight into the engine system and reveal how your engine is actually performing with minimal intrusion. Compression, airflow, valve timing and back pressure can all be measured in one hit, giving you information that can help in solving common problems.

More information on The WPS500X Pressure Transducer >>

One of the hardest problems to diagnose is the intermittent fault – it may be a customer complaint or may even have triggered a fault code, but it never appears when you are looking. With PicoScope you don’t need to worry about missing glitches or other transient events as the software can store the last ten thousand waveforms in its circular waveform buffer.

Used with triggers or mask limit testing, your PicoScope can be configured to save everything leading up to and following that intermittent event in the waveform buffer. PicoScope can also be set up with alarms to beep or send you an email to let you know when it has found the problem.

The buffer navigator is how PicoScope lets you navigate and search through waveforms effectively letting you turn back time.  Mask limit testing can also be used to scan through each waveform in the buffer looking for mask violations and providing instant visual identification of the problem area.

Focus piece: Waveform library

PicoScope Automotive includes a great feature that allows the Pico community to benefit from each other’s experiences. Under the File menu on the toolbar you will see Waveform Library Browser, this feature enables you to search and make use of a global database of waveforms uploaded by PicoScope users from around the world, and contribute yours to share with others.

More information on Waveform library >>




The PicoScope Diagnostic Oscilloscopes have a deep buffer memory, which allows them to provide high sampling rates across long timebases. For example, with a 250 MS buffer the PicoScope 4425 can sample at 100MS/s on 4 channels all the way down to 50 ms/div to give a total capture time of 500 ms. The zoom and scroll functions enable you to navigate and display all the data in detail. The zoom overview shows you the full waveforms on all channels, and allows you to easily control the zoom area by just clicking and dragging.