DTC P0611: Fuel Injection Control Module Internal Fault: Description
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.
The Fuel Injection Control Module (FICM) has the ability to perform internal circuit checks on the FICM microprocessor, status of the monitoring module, and status of the FICM A/D conversion module. If the FICM senses a problem in the FICM circuits, the FICM will send an error message to the Engine Control Module (ECM). If this condition exists, DTC P0611 will set.