Chart 3 Ignition Control Check

Chart 3 Ignition Control Check:

Ignition System:

Circuit Description

The ignition control check verifies that the ignition control and bypass circuits between the PCM and Ignition Control Module (ICM) are functioning properly. This chart requires J 39200 voltmeter and J 35616 jumper kit.

Notes on Chart

1. CKT 424 is the bypass circuit and should be low at key "ON".

2. CKT 423 is ignition control, EST, circuit and should be low with the ICM not receiving crankshaft position sensor pulses.

3. CKT 424, bypass circuit, should be high with engine running.