For 1990-2009 cars only
Troubleshooting Hints -- Data Link Connector (DLC)
- Inspect the condition of the HORNS circuit breaker. If the circuit breaker is open, locate and repair the cause of the overload and then replace the circuit breaker.
- Inspect Grounds G 102 and G 101 to make certain that they are clean and tight.
- Use a scan tool to test for an open or short to ground in CKT 448 (WHT/BLK) or CKT 461 (ORN) -- gas engine or CKT 1807 (PPL) -- diesel engine between the DLC and engine control module (ECM) if the ECM is not accessible.
- Use the scan tool to test for an open or short to ground in CKT 799 (TAN/WHT), hydraulic brakes, between the DLC and the electronic brake control module (EBCM) if the EBCM is not accessible.
- Inspect for loose or damaged terminals in the DLC. Repair any damage that is found.
- Inspect for poor or damaged connections at the component and in-line harness connectors before replacing any components.
- Use digital multimeter to check for 12 volts between terminal 16 of the DLC and chassis ground. Repair the open in CKT 140 (ORN) between the IP fuse block and terminal 16 of the DLC if the test does not indicate the presence of 12 volts.
- Use a selfpowered test lamp to test for continuity between terminal 4 and terminal 5 of the DLC. If an open is detected in either circuit, repair the open in the circuit.
- Inspect for broken (or partially broken) wire inside the insulation. This condition could cause system malfunction but prove to test good in a continuity or voltage test with the system disconnected. These circuits may be intermittent or resistive when in operation. If possible test for a voltage drop when the system is operational.
- Inspect for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.
