Diesel Data: Automotive Repair

Low Oil Pressure Indicator Circuit Troubleshooting - Short




Low Oil Pressure Indicator Circuit Troubleshooting - Short

1. Connect the HDS to the DLC. Initial Inspection and Diagnostic Overview

2. Turn the ignition switch to ON (II).

3. Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit. Testing and Inspection

4. Check for DTCs. Initial Inspection and Diagnostic Overview If a DTC is present, diagnose, and repair the cause before continuing with this test.

5. Start the engine, and check the OIL PRESSURE SWITCH in the PGM-FI DATA LIST with the HDS.

Is OFF indicated?

YES -

Replace the gauge control module Gauge Control Module Replacement.�

NO -

Go to step 6.

6. Turn the ignition switch to LOCK (0).

7. Check the oil pressure switch.

Is the oil pressure switch OK?

YES -

Go to step 8.

NO -

Do the oil pressure test. If the oil pressure OK, replace the oil pressure switch Service and Repair.�

8. Turn the ignition switch to ON (II), and jump the SCS line with the HDS, then turn the ignition switch to LOCK (0).

NOTE: This step must be done to protect the PCM from damage.

9. Disconnect PCM connector B (49P) and the oil pressure switch connector.

10. Check for continuity between the oil pressure switch connector and body ground.





Is there continuity?

YES -

Repair a short to ground in the wire between the oil pressure switch and PCM.�

NO -

Update the PCM if it does not have the latest software, PCM Update or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM Service and Repair.�