Coil-on-plug - primary and secondary voltage (probe)

The purpose of this test is to investigate the operation of the primary and secondary ignition circuits within an externally grounded Coil-On-Plug (COP) style ignition system. 

 

WARNING

This test involves measuring a potentially hazardous voltage.

Please ensure you follow manufacturers' safety instructions and working practices and ensure the rated voltage for all accessories you are using meets or exceeds the expected voltage.

To avoid possible damage to your scope, you may need to use an attenuator for this test.

Scopes with a 200 V range, such as PicoScope 4x25 models, do not need an attenuator for this test.

All other PicoScope Automotive models need an attenuator on the channel input. You can use either a 10:1 or a 20:1 attenuator provided that you adjust the PicoScope software accordingly. Select from the appropriate Channel Options menu:

  • Probe > x10 for a 10:1 attenuator
  • Probe > x20 for a 20:1 attenuator

 

How to perform the test

View connection guidance notes.

 

  1. Use manufacturer data to identify the coil circuit functions.
  2. Connect PicoScope Channel A. to the coil switched earth circuit.
  3. Connect the COP probe to PicoScope Channel B and to engine earth.
  4. Start the engine and allow it to idle.
  5. Minimize the help page. You will see that PicoScope has displayed an example waveform and is preset to capture your waveform.
  6. Start the scope to see live data.
  7. Place the COP probe squarely onto the top of the COP unit to be tested, this will now pick up the secondary pattern.
  8. With your waveforms on screen stop the scope.
  9. Stop the engine and switch off the ignition.
  10. Use the Waveform Buffer, Zoom and Measurements tools to examine your waveform.

Example waveform

Waveform notes

The waveforms that you will see during this test are discussed in these topics:

  • Channel A: Primary ignition waveform
  • Channel B: Secondary COP ignition waveform

Waveform Library

Go to the drop-down menu bar at the lower left corner of the Waveform Library window and select, COP (Coil on plug ignition) secondary voltage.

GT078

Disclaimer

Suitable accessories

  • Coil On Plug (COP) and Signal Probe

    £179.00

  • Multimeter Probes

    £6.00

Help us improve our tests

We know that our PicoScope users are clever and creative and we’d love to receive your ideas for improvement on this test. Click the Add comment button to leave your feedback.

Add comment

Your email address will not be published. Required fields are marked *

Guided test: Coil-on-plug - primary and secondary voltage (probe)