Diagnostic Aids

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.

A false or incorrect AT OSS or AT ISS signal can set DTC P0730.
DTC P0894 detects an incorrect gear ratio in fourth gear with TCC applied.
Inspect for any improperly installed aftermarket equipment.
Sticking or contamination of shift valves may cause intermittent incorrect gear ratios.
Refer to Shift Solenoid Valve State And Gear Ratio .
DTC P0730 defaults to an elevated line pressure which may result in partial TCC apply. This may produce an idle surge that could stall the engine.