Conditions for Running the DTC

WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

No VSS assembly DTCs P0502 or P0503.
The system voltage is 10-18 volts.
The engine speed is greater than 450 RPM for 5 seconds.
The engine is not in fuel cutoff.
The engine torque is 54-542 N.m (40-400 lb ft).
The engine vacuum is 0-105 kPa (0-15 psi).