On-Board Diagnostic System: Inspection

The Powertrain Control Module (PCM) monitors critical input and output circuits of the charging system, making sure they are operational. A Diagnostic Trouble Code (DTC) is assigned to each input and output circuit monitored by the On-Board Diagnostic (OBD) system. Some charging system circuits are checked continuously and some are checked only under certain conditions.

Refer to Diagnostic Trouble Codes in POWERTRAIN DIAGNOSTIC PROCEDURES article for more DTC information. This will include a complete list of DTC's including DTC's for the charging system.

To perform a complete test of the charging system, refer to POWERTRAIN DIAGNOSTIC PROCEDURES article and the scan tool. Perform the following inspections before attaching the scan tool.

1. Inspect the battery condition. (Refer to ELECTRICAL/BATTERY SYSTEM - DIAGNOSIS AND TESTING) for procedures.
2. Inspect condition of battery cable terminals, battery posts, connections at engine block, starter solenoid and relay. They should be clean and tight. Repair as required.
3. Inspect all fuses in both the fuseblock and Power Distribution Center (PDC) or IPM (if equipped) for tightness in receptacles. They should be properly installed and tight. Repair or replace as required.
4. Inspect generator mounting bolts for tightness. Replace or tighten bolts if required. (Refer to ELECTRICAL/CHARGING - SPECIFICATIONS) .
5. Inspect generator drive belt condition and tension. Tighten or replace belt as required. Refer to COOLING .
6. Inspect decoupler pulley (if equipped). Ensure decoupler pulley is driving the alternator rotor.
7. Inspect automatic belt tensioner (if equipped). Refer to COOLING for more information.
8. Inspect generator electrical connections at generator field, battery output and ground terminal (if equipped). Also check generator ground wire connection at engine (if equipped). They should all be clean and tight. Repair as required.