Diagnostic Procedure
- Perform battery inspection test. See BATTERY TESTING & INSPECTION under ON-VEHICLE TESTING. After performing inspection, go to next step.
- Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, see BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Access the Class 2 Power Mode in the Diagnostic Circuit Check on the scan tool. Rotate the ignition switch through all positions while observing the Class 2 Power Mode parameter. The ignition switch parameter reading should match the ignition switch position for all switch positions. If reading is as specified, go to next step. If reading is not as specified, see appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- Turn ON the ignition, with the engine OFF. Attempt to communicate with each of the following modules on the class 2 serial data circuit:
- Body Control Module (BCM).
- Instrument Panel Cluster (IPC).
- Powertrain Control Module (PCM).
- Select display DTC function for each module. Record all displayed DTCs, status of displayed DTCs and module that set DTC. If DTCs are displayed, go to next step. If no DTCs are displayed, repair charging system by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.
- If scan tool does not display DTCs which begin with "U", go to next step. If scan tool displays DTCs which begin with "U", perform appropriate test. See BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
- If scan tool displays DTCs B1000, perform appropriate. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in BODY CONTROL MODULES article. If scan tool displays any other DTCs which begin with "B", see DIAGNOSTIC TROUBLE CODE DEFINITIONS .
NOTE:
The engine may start during the following step. Turn OFF the engine as soon as you have observed the Crank power mode.