Retained Accessory Power Diagnostic System Check
WARNING: This page is about a different car, the 2001 GMC Safari and 2001 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Presence of DTCs which begin with "U" indicate some other module on class 2 serial data line is not communicating.
- Connect scan tool to Data Link Connector (DLC). DLC is located under left side of instrument panel. If scan tool powers up, go to next step. If scan tool does not power up, go to TEST E: SCAN TOOL DOES NOT POWER UP under SYSTEM TESTS.
- Turn ignition switch to RUN position. Attempt to establish communication with Body Control Module (BCM) on class 2 serial data circuit. If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
- Using scan tool, select DISPLAY DTCS function. Retrieve and record any BCM DTCs and their status. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair retained accessory power system as necessary. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- If scan tool does not display any DTCs which begin with a "U", go to next step. If scan tool displays any DTCs which begin with a "U", go to TEST D: TEST D: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE under SYSTEM TESTS.
- If scan tool displays any other DTC, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .