J2000/Sunbird V6-191 3.1L (1992)
Vehicle Speed Sensor: Symptom Related Diagnostic Procedures
1.
Connect a Scan Tool to the ALDL Connector. Drive the vehicle. Observe the Speedometer and compare it to the vehicle speed shown on the Scan
Tool.
^
If both the Speedometer and Scan Tool display the same approximate speed, check for correct tire size, ECM MEM-CAL and Vehicle Speed
Sensor.
^
If the Scan Tool and Speedometer do not display the same approximate speed, replace or exchange the Instrument Cluster.
ALTERNATE TEST
^
If the Kent Moore Tool J38522 is available, do the following test.
2.
Connect a Scan Tool to the ALDL connector. Disconnect the Vehicle Speed Sensor connector. Connect a lead between the J38522 vehicle speed
generator's red output terminal and the Vehicle Speed Sensor connector terminal A (LT BLU). Connect a lead between the J38522 generator's black
output and terminal B (DK GRN/YEL). Plug the generator into the Cigar Lighter. Select 30 V P-P sine wave and set the frequency at 600 hz.
Observe the Speedometer and compare to the vehicle speed shown on the Scan Tool.
^
If both the Speedometer and Scan Tool display the same approximate speed, check for correct tire size, ECM MEM-CAL and Vehicle Speed
Sensor.
^
If the Scan Tool and Speedometer do not display the same approximate speed, replace or exchange the Instrument Cluster.
