Ignition System

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

Test for the proper secondary voltage output with Spark Tester (J 26792), or equivalent.
Inspect the spark plugs for correct operation and good ignition system performance.
Inspect the ignition coil boots for damage.
Observe the IAC MOTOR COMMAND parameter on the scan tool at idle, while operating rear defogger, A/C system, or headlights. IAC MOTOR COMMAND parameter should increase 2-7 percent when operating the engine loads. If IAC MOTOR COMMAND parameter remains fixed, check for a short to ground in the Diagnostic Request circuit from the PCM to Data Link Connector (DLC) terminal No. 13.