Grand Prix V6-204 3.4L DOHC (1992)
Vehicle Speed Sensor: Symptom Related Diagnostic Procedures
Connect a Scan Tool to the ALDL Connector. Drive the vehicle. Observe the Speedometer and Scan Tool speed display.
^ If the Speedometer and Scan Tool agree, check the ECM MEM-CAL, the Vehicle Speed Sensor, and for the correct tire size.
^ If the Speedometer and Scan Tool disagree, service the Instrument Cluster.
