DLC Diagnosis Or No Scan Tool Data
- Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
- Turn ignition on with engine off. Connect a test light between DLC battery feed circuit and ground circuit. See WIRING DIAGRAMS - 3.1L article. If test light illuminates, go to step 4). If test light does not illuminate, go to next step.
- Using a test light connected to ground, probe DLC battery feed circuit. See WIRING DIAGRAMS - 3.1L article. If test light illuminates, go to step 9). If test light does not illuminate, go to step 10).
- Turn ignition on with engine off. Using DVOM connected to ground, probe DLC class 2 serial data circuit. See WIRING DIAGRAMS - 3.1L article. DVOM should read zero volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step 7).
- Turn ignition off. Disconnect PCM connector. Turn ignition on with engine off. Using DVOM connected to battery voltage, probe DLC class 2 serial data circuit. See WIRING DIAGRAMS - 3.1L article. DVOM should read zero volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step 8).
- Check for open in class 2 serial data circuit between DLC and PCM. Repair as necessary. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . If circuit is okay, go to step 11).
- Check for short to voltage in class 2 serial data circuit. Repair as necessary. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK . If circuit is okay, go to step 11).
- Locate and repair short to ground in class 2 serial data circuit. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .
- Locate and repair open in DLC ground circuits. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .
- Locate and repair open or short to ground in DLC battery feed circuit. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .
- Replace PCM. Perform PCM relearn procedures. After repairs, perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .