Additional Checks

WARNING: This page is about a different car, the 2003 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

Check the Torque Converter Clutch (TCC) system for proper operation. See appropriate DIAGNOSIS article in TRANSMISSIONS.
If the scan tool readings are normal, and there are no engine mechanical faults, fill the fuel tank with a premium gasoline that has a minimum octane reading of 92 and re-evaluate the vehicle.