Service Precautions

Before proceeding with diagnosis, observe following precautions:

Ensure battery is fully charged.
Probe PCM connector from pin side. DO NOT backprobe PCM connector or probe wires through insulation.
DO NOT cause short circuits when performing electrical tests. This will set additional DTCs, making diagnosis of original problem more difficult.
DO NOT use a test light in place of a voltmeter.
Always begin repair with lowest DTC number (MIL) or first DTC displayed (scan tool).
Always perform appropriate verification (VER) test after repairs are made.
Always disconnect scan tool after use.
Always disconnect scan tool before charging battery.

CAUTION: Before entering on-board diagnostics, check charging system for other problems. See INITIAL CHECKS under TROUBLE SHOOTING. DO NOT connect scan tool to vehicle if battery charger is connected, as scan tool damage will result.

NOTE: PCM cannot diagnose every charging system problem. If fault still exists after performing self-diagnostic procedures, proceed to ON-VEHICLE TESTING .