Conditions for Running the DTC

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

The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
TCM initialization is in process or engine speed is greater than 200 RPM and less than 7,500 RPM for 5 seconds.
The TCM must auto-detect G solenoid.