Component Test

Vehicle Speed Sensor Circuit:

Component Test
1. The Vehicle Speed Sensor (VSS) is mounted on the rear of the instrument panel. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/VSS for procedures in removing the instrument panel.

Testing VSS:

2. Connect an ohmmeter to terminals 59 and 2, as shown.
3. Check for continuity/no-continuity as the speedometer cable shaft is rotated.
Note: For each rotation continuity/no-continuity should be indicated 4 times.

Harness Test
1. Disconnect the ECM harness connector.
2. Connect an ohmmeter to terminal 18.
3. Check for continuity/no-continuity as the speedometer cable shaft is rotated.
4. Disconnect the speed sensor harness connector.
5. Using a voltmeter with a minimum impedance of 10 Meg. ohms, measure the voltage at the speed sensor harness connector terminal 59.

Voltage:
4.5 - 4.9 Volts.

6. Check for continuity of the ground circuit of the Vehicle Speed Sensor, between the harness connector terminal 2 and ground.

Continuity:
Should exist


If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.
If the same trouble code reoccurs, it is possible that there is an intermittent failure of the component or the ECM. Check for looseness at all harness junctions and test for an intermittent failure.