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Glow Plug Relay (CALIFORNIA): Removal

CAUTION: 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® (UE1) with Back Up Battery: The Back Up Battery is a redundant power supply to allow limited OnStar® functionality in the event of a main vehicle battery power disruption to the VCIM (OnStar®module). Do not disconnect the main vehicle battery or remove the OnStar® 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® module in any way while the ignition is On or with RAP activated may cause activation of the OnStar® 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.
Fig 1: Glow Plug Relay, Mount & Bolts
GM365439Courtesy of GENERAL MOTORS CORP.
  1. Remove the negative battery cables.
  2. Remove the upper intake manifold cover by loosening the mounting bolts.
  3. Release all three wiring harness connectors at the glow plug relay(1).
  4. Remove the glow plug battery feed nut and wire.
  5. Remove the relay mounting bolt.
  6. Remove the glow plug relay (1).