Retrieving Diagnostic Trouble Codes
NOTE:
If using a generic scan tool or using DRBIII scan tool in generic scan tool mode, Powertrain Control Module (PCM) may stop communications with scan tool. This applies to vehicles with a build date prior to 11-30-99. It may appear that sensor values are not updating on generic scan tool. This condition may occur at any time during communications between PCM and generic scan tool. If this condition occurs, see technical service bulletin No. 08-39-99 for recommended repair procedure.
NOTE:
Ensure battery is fully charged before proceeding with Diagnostic Trouble Code (DTC) retrieval.
- Turn ignition off. DTCs can only be retrieved using a scan tool. Connect scan tool to Data Link Connector (DLC) located below instrument panel, near steering column. See Fig 1 Turn ignition on, with engine off. Using scan tool manufacturer's instructions, read and record DTC (generic scan tool) or DTC message (DRB scan tool), and freeze frame data.
- If scan tool displays NO RESPONSE, go to SCAN TOOL ERROR MESSAGES . If scan tool will not power up, check for loose cable connections or bad cable. If cable connections and cable are okay, measure voltage at DLC power terminal No. 16 (Tan/Black wire). Voltage should be at least 11 volts. If voltage is not as specified, check wiring circuit and fuse No. 19 (20-amp) in Power Distribution Center (PDC). PDC is located in right side of engine compartment, next to battery. Repair wiring or replace fuse as necessary.
- If scan tool displays USER-REQUESTED COLD BOOT error or USER-REQUESTED WARM BOOT error, or any other error message, record entire displayed error message and follow scan tool manufacturer's instructions.
- If scan tool displays a bus failure error message, this indicates a scan tool failure or a bus circuit failure. To diagnose and repair bus circuit failure, see COMMUNICATIONS under SYSTEM TESTS in BODY CONTROL MODULES - CHEROKEE article in ACCESSORIES & EQUIPMENT.
- If any DTCs are displayed, perform appropriate diagnostic test. See DTC MESSAGES & CODES
table under DIAGNOSTIC TROUBLE CODE DEFINITIONS. After repair is complete, clear DTCs from PCM memory and perform appropriate verification test. Verification tests are located at the end of the diagnostic tests. If no DTCs are displayed, go to one of the following:
- For starting or driveability problems, go to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom.
- For speed control problems and servicing information, see appropriate CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.
- For charging system problems, see appropriate GENERATORS & REGULATORS article in STARTING & CHARGING SYSTEMS.