Secondary ignition pickup (capacitive with BNC)
20 A / 60 A DC (low amps) current clamp
Multimeter Probes
*At Pico we are always looking to improve our products. The tools used in this guided test may have been superseded and the products above are our latest versions used to diagnose the fault documented in this case study.
The purpose of this test is to examine and compare the primary current and voltage vs the secondary voltage within a DIS unit.
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.
WARNING
Uninsulated HT pickups are designed to clip around double-insulated HT leads only – they are not designed for direct connection to a hazardous live voltage.
To prevent injury or death, when connecting or disconnecting an HT pickup:
View connection guidance notes.
Note
If the secondary voltage waveform appears inverted then this is because the output is positive-fired. Move the secondary ignition pick up onto a different HT lead.
Alternatively, you can change the settings to look at a positive-fired coil by selecting the settings for channel B and changing the probe from Secondary Ignition Probe (Inverted) to Secondary Ignition Probe (Pos).
Note
The orientation of the current clamp relative to the wire will determine whether it has a positive or negative output. If a live waveform does not appear on your screen, or appears to be inverted, try reversing the orientation of the clamp.
Note
This helpfile refers to a 10:1 attenuator. If you are using a 20:1 attenuator please adjust the Probe settings for the relevant channel. These settings can be found under the Channel Options button, then: Probe > 20:1 Attenuator.
These known good waveforms have the following characteristics:
GT394
Disclaimer
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure.
Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test
settings.
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