DTC P1658: Fuel Injector Control Module Driver Circuits: Description
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 Fuel Injection Control Module (FICM) self monitors driver performance and sends this information to the Engine Control Module (ECM) through the CAN system. If a fault is detected in the driver circuits, the FICM will signal the ECM, and DTC P1658 will set. This is an internal circuit fault, and can not be caused by external failures.