Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the X175 harness connector at the transmission.
- Ignition ON, engine OFF, verify with a scan tool the TR Sw. A/B/C/P parameters are all On.
- If not the specified value, test the affected IMS signal circuit for a short to ground. If the circuit tests normal, replace the TCM.
- Connect a 3A fused jumper wire between the IMS signal circuit terminals listed below and low reference circuit terminal H. Verify with a scan tool that the TR Sw. A/B/C/P parameters changed from On to Off.
- IMS signal circuit A terminal V
- IMS signal circuit B terminal U
- IMS signal circuit C terminal T
- IMS signal circuit P terminal W
- If not the specified value, test the affected IMS signal circuits and low reference circuit for an open/high resistance. If the circuits test normal, replace the TCM.
- Ignition OFF, remove the transmission oil pan and transmission internal filter. Refer to Oil Pan Replacement .
- Test the internal wiring harness IMS signal circuits and low reference circuits for an open/high resistance and short to ground.
- If circuits test normal, replace the IMS. Refer to Transmission Internal Mode Switch Replacement .
- Replace the internal wiring harness. Refer to Wiring Harness Replacement .