Vehicle Speed Signal Circuit Troubleshooting
Vehicle Speed Signal Circuit TroubleshootingBefore testing:
- Check to see if Diagnostic Trouble Code (DTC) P0720 (9) is indicated. If it is, troubleshoot the DTC.
- Inspect the No. 9 (10 A) fuse in the driver's under-dash fuse/relay box.
- Check for continuity between the gauge assembly 14P connector C9 and C10 terminals and body ground (G501).
1. Raise the vehicle, and make sure it is securely supported.
2. Disconnect gauge assembly connector C (14P).
3. Connect the C2 terminal to the positive probe of a voltmeter, and connect the negative probe to body ground. To prevent damage to the gauge assembly, lay the gauge assembly on a shop towel.
4. Put the vehicle in neutral with the ignition switch ON (II).
5. Slowly rotate (over 3 mph (2 km/h)) one wheel with the other wheel blocked.
Does voltage pulse from 0 to about 5 V or more?
YES - Replace the gauge assembly.
NO - Turn the ignition switch OFF, and go to step 6.
6. Connect the No. 9 terminal of the PCM 32P connector to the positive probe of a voltmeter, and connect the negative probe to body ground.
7. Put the vehicle in neutral with the ignition switch ON (II).
8. Slowly rotate (over 3 mph (2 km/h)) on wheel with the other wheel blocked.
Does voltage pulse from 0 to about 5 V or more?
YES - Repair open in the BLU/WHT wire between the gauge assembly and the PCM, the cruise control unit, or the multiplex control unit, driver's.
NO - Turn the ignition switch OFF, and go to step 9.
9. Disconnect the 32P connector from the PCM.
10. Check for continuity between No. 9 terminal and body ground.
Is there continuity?
YES - Repair short to ground in the BLU/WHT wire between the PCM and the gauge assembly, the cruise control unit, or the driver's multiplex control unit
NO - Check for these problems:
- Bent, loose or corroded terminals.
- A faulty PCM.