Express 4500 V8-6.0L (2010)
Crankshaft Position Sensor: Service and Repair
Crankshaft Position Sensor Replacement
Removal Procedure
Warning
Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any
electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed
electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
For Vehicles equipped with OnStar(R) (UE1) with Back Up Battery:
The Back Up Battery is a redundant power supply to allow limited OnStar(R) functionality in the event of a main vehicle battery power disruption to the
VCIM (OnStar(R)module). Do not disconnect the main vehicle battery or remove the OnStar(R) fuse with the ignition key in any position other than
OFF. Retained accessory power (RAP) should be allowed to time out or be disabled (simply opening the driver door should disable RAP) before
disconnecting power. Disconnecting power to the OnStar(R) module in any way while the ignition is On or with RAP activated may cause activation of
the OnStar(R) Back-Up Battery (BUB) system and will discharge and permanently damage the back-up battery. Once the Back-Up Battery is activated it
will stay on until it has completely discharged. The BUB is not rechargeable and once activated the BUB must be replaced.
Note: Perform the Crankshaft Position System Variation Learn (See: Testing and Inspection) when the CKP sensor is removed or replaced.
Access To CKP Sensor
1. Disconnect the negative battery cable.
2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (See: Maintenance/Vehicle Lifting/Service and Repair).
3. Remove the starter. Refer to Starter Replacement (V8) (See: Starting and Charging/Starting System/Starter Motor/Service and Repair)Starter
Replacement (V6) (See: Starting and Charging/Starting System/Starter Motor/Service and Repair)Starter Replacement (Diesel) (See: Starting
and Charging/Starting System/Starter Motor/Service and Repair).
4. Disconnect the crankshaft position (CKP) sensor electrical connector.
