GMC 12629472 Ignition Coil

Disconnect the cable from the negative battery terminal. Remove the air intake duct and resonator from the throttle body. The engine wiring harness crosses the valve cover in a large conduit, which must be removed to access the front coils. A number of electrical connectors must be disconnected. From below the vehicle, disconnect the connector at the oil pressure sensor and unclip the harness from the oil filter adapter and the power steering pump. Disconnect the camshaft position sensor and camshaft position sensor actuator solenoid. Unclip these wires from the valve cover. On top of the engine disconnect the ECT, the fuel injector harness connector, and the oxygen sensor. Pop the engine harness conduit from its tabs on the valve cover. Pull up the engine harness conduit to access the first ignition coil. Disconnect the electrical connector from the ignition coil. Disengage the connector lock then unplug the electrical connector. Unscrew the ignition coil mounting bolt and remove the coil from the valve cover. Unscrew the ignition coil mounting bolt then pull the coil from the valve cover. Check the seals on the coils for cracks or other signs of damage, replacing them as necessary. Install new seal(s) on the ignition coil(s) if they are damaged or hardened. Installation is otherwise the reverse of removal. Tighten the mounting bolt.

For six-cylinder models,Disconnect the cable from the negative battery terminal. Remove the air intake duct and resonator from the throttle body. Disconnect the electrical connector from the ignition coil (Disengage the connector lock then unplug the electrical connector). Remove the ignition coil mounting bolt and remove the assembly from the valve cover (remove the ignition coil mounting bolt then pull the coil from the valve cover). Check the seals on the coils for cracks or other signs of damage, replacing them as necessary (Install new seal(s) on the ignition coil(s) if they are damaged or hardened). Installation is otherwise the reverse of removal. Tighten the mounting bolt to the specific torque.V8 MODELS: Disconnect the cable from the negative battery terminal. The ignition coils may be removed from each cylinder bank as a complete assembly or removed from the mounting bracket individually. If removing the complete assembly, disconnect the ignition coil main electrical connector. Disconnect the spark plug wires from the spark plugs. Remove the ignition coil bracket mounting nuts/bolts and remove the assembly from the engine. If removing the individual coil, disconnect the spark plug wire from the coil. Remove the ignition coil mounting screws and remove the ignition coil from the bracket (Remove the ignition coil mounting screws). Installation is the reverse of removal.

Disconnect the cable from the negative battery terminal. Remove the air intake duct and resonator from the throttle body. The engine wiring harness crosses the valve cover in a large conduit, which must be removed to access the front coils. A number of electrical connectors must be disconnected. From below the vehicle, disconnect the connector at the oil pressure sensor and unclip the harness from the oil filter adapter and the power steering pump. Disconnect the camshaft position sensor and camshaft position sensor actuator solenoid. Unclip these wires from the valve cover. On top of the engine disconnect the ECT, the fuel injector harness connector, and the oxygen sensor. Pop the engine harness conduit from its tabs on the valve cover. Pull up the engine harness conduit to access the first ignition coil. Disconnect the electrical connector from the ignition coil. Disengage the connector lock then unplug the electrical connector. Unscrew the ignition coil mounting bolt and remove the coil from the valve cover. Unscrew the ignition coil mounting bolt then pull the coil from the valve cover. Check the seals on the coils for cracks or other signs of damage, replacing them as necessary. Install new seal(s) on the ignition coil(s) if they are damaged or hardened. Installation is otherwise the reverse of removal. Tighten the mounting bolt.