Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
P0815
- Select the Driver Shift Request parameter.
- Disconnect the automatic transmission RSM shift switch connector.
- If the parameter status changes from Upshift to Invalid, replace the RSM shift switch.
- If the parameter status does not change, replace the BCM.
P0816
- Select the Driver Shift Request parameter.
- Disconnect the RSM shift switch connector.
- If the parameter status changes from Downshift to Invalid, replace the RSM shift switch.
- If the parameter status does not change, replace the BCM.
P0826
- Test the 12-volt reference circuit and the tap up and tap down switch signal circuit for a short to ground.
- If the circuits test OK, test the 12-volt reference circuit and the tap up and tap down signal circuit for an open or short to voltage.
- Test the RSM shift switch for correct resistance value, 8.11-8.39 ohms.
- If the resistance is not within specifications, replace the switch assembly.
- If the resistance is within specifications, replace the BCM.