Diagnostic Aids

WARNING: This page is about a different car, the 2003 Saturn LW300, 2003 Saturn LW200, 2003 Saturn L300, and 2003 Saturn L200. However, it is still accessible from the selected car via links, so may be relevant.

If TCM DTCs P0502 or P0503 are set, diagnose these DTCs first.
If an output speed sensor signal circuit fault is occurring, a vehicle speed of 0 km/h (0 mph) will be sent to the ECM and the ECM will set DTC P0500.
To locate an intermittent problem, use the scan tool to monitor vehicle speed in the ECM data list with the vehicle raised and the drive wheels moving greater than 5 km/h (3 mph). If an intermittent output speed sensor signal is occurring, vehicle speed on the scan tool will go to 0 km/h (0 mph).