Vehicle Speed Signal Circuit Troubleshooting
Special Tools Required
Test Harness 07LAJ-PT3020A
Before testing, inspect the No. 4 (7.5 A) fuse in the under-dash fuse/relay box.
- Disconnect the 3P connector from the VSS (vehicle speed sensor) (A).
- Connect the test harness only to the engine wire harness and the VSS.
- Connect the RED test harness clip (B) to the positive probe of an ohmmeter. Cover the WHT (C) and GRN (D) test harness with protective tape (E).
- Turn the ignition switch ON (II).
- Check for voltage between the RED test harness clip and body ground.
Is there less than 1 V?
- YES -Go to step 6.
- NO -Repair open or loose connection on the BLK wire between the VSS and body ground (G101, G102*).
*: '02-06 models
- Turn the ignition switch OFF.
- Connect the WHT test harness clip (A) to the positive probe of a voltmeter, and connect the RED test harness clip (B) to the negative probe.
- Turn the ignition switch ON (II).
Is there battery voltage?
- YES -Go to step 9.
- NO -Repair open in the BLK/YEL wire between the VSS and the under-dash fuse/relay box.
- Disconnect the WHT test harness clip (A).
- Disconnect the test harness from the VSS (B).
- Connect the GRN test harness clip (C) to the positive probe of a voltmeter.
Is there 5 V or more?
- YES -Go to step 12.
- NO -Repair short in the BLU/WHT wire between the VSS and the ECM.
- Turn the ignition switch OFF.
- Connect the other test harness connector (A) to the VSS (B).
- Raise the front of the vehicle, and make sure it is securely supported.
- Put the vehicle in neutral with the ignition switch ON (II).
- Slowly rotate one wheel with the other wheel blocked.
Does voltage pulse from 0 to about 5 V or more?
- YES -Go to step 17.
- NO -Replace the VSS.
- Disconnect gauge assembly connector A (30P).
- Connect a voltmeter between the BLU/WHT wire and body ground.
- Slowly rotate one wheel with the other wheel blocked.
Does the meter indicate pulsing voltage?
- YES -Replace the speedometer.
- NO -Repair open in the BLU/WHT wire between the VSS and the speedometer.