NA - Testing Notes

NOTE:
You should enter this Pinpoint Test only when you have been directed here from Diagnostic Routines,

REMEMBER:
To prevent the replacement of good components, be aware that the following non-Electronic Engine Controls (EEC) areas may be at fault:

- Ignition Control Module (ICM)

- Ignition coil

- Spark plugs and high tension cables

- Distributor

- Arcing of secondary ignition components

This Pinpoint Test is intended to diagnose only the following:

- Harness circuit: Ignition Diagnostic Monitor (IDM)

- Powertrain Control Module (PCM) (12A650)

Description:
The Ignition Diagnostic Monitor is an input signal to the PCM that verifies spark function based on the flyback voltage created by the ignition coil primary discharge. This signal is transmitted from the ICM to the PCM. The IDM signal consists of a single pulse for each successful ignition event. Lack of an IDM pulse is used as an indication of intermittent and/or missing spark events.