Diagnostic Aids
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
There is no external failure that can cause DTC P1658 to set. This DTC is an internal circuit failure. An intermittent or hard code will result in FICM replacement.