DTC 57 - Pcm 5-Volt Shorted: Notes
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1994 GMC Yukon, 1994 GMC Suburban, 1994 GMC Pickup, 1994 GMC Cab & Chassis, and 1994 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The 5-volt reference is a non-varying calculated voltage. DTC 57 will set when 5-volt reference is less than one volt. PCM will default to backup fuel, no EGR and no turbo boost.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- This step confirms that a DTC is still present.
- This step checks that a 5-volt reference is present from the PCM.
- This step determines if a short to ground is present in the 5-volt reference circuits or in the PCM.