GMC 12638824 Ignition Coil Assembly

You can Select Your Vehicle to check if 12638824 fits your vehicle.

To remove the ignition coil, remove the intake manifold cover, and disconnect the electrical connector from the ignition control module. Replace if necessary and coat the interior of each boot with silicone dielectric compound before reinstallation. For other models, turn the ignition key to OFF, remove the engine cover, disconnect the electrical connector from the ignition coils, remove the coil mounting bolt(s) and pull the coil(s) from the valve cover.

Disconnect the cable from the negative battery terminal. Remove the engine cover. For 3.4L V6 models, label and disconnect the spark plug wires from the coil pack. Disconnect the electrical connectors, then remove the mounting fasteners from the coil pack. Remove the coil pack. For all models except 3.4L V6 models, remove the air cleaner outlet duct if it will interfere with the coil(s) you're removing. Disconnect the electrical connector and mounting fastener from the ignition coil. Remove the ignition coil from the spark plug. For all models, apply a little silicone dielectric compound to the inside of each boot before installing it. Installation is the reverse of removal.

Four-cylinder models require the removal of the ignition control module from the top of the coil pack. This involves removing the four mounting bolts and pulling the module from the spark plugs and valve cover. To detach the Ignition coil pack, remove these four bolts and pull the coil pack straight up. The cover can be removed by taking out the three screws. If replacing the ignition coil pack, remove the four boots from the coil pack and inspect them for cracks, tears and deterioration, replacing them as necessary. For 2002 and 2003 V6 models, remove the intake manifold, which can be left in the engine compartment as long as there is access to the coil packs. Disconnect the wiring harness from the coil pack(s) and remove the two mounting bolts. The coil pack can then be removed. If the module is difficult to remove, bolts can be screwed into it for more leverage to aid in wiggling it free. The gasket should also be removed. For 2004 and later V6 models, start by removing the engine cover. Disconnect the electrical connector and mounting bolt from the ignition coil. On 3.5L V6 models, press the tab to disconnect the wiring, then remove the mounting screw. The ignition coil can then be removed from the spark plug. For all models, apply a little silicone dielectric compound to the inside of each boot before installing it. Installation is the reverse of removal.

The first step is to disconnect the cable from the negative battery terminal.

Disconnect the cable from the negative terminal of the battery.

Remove the ignition control module in order to remove the cover from the ignition coil pack. Also, remove the four boots from the coil pack and inspect them for cracks, tears, and deterioration. Replace any damaged boots. Before installing the boots on the ignition coil pack, coat the interior of each boot with silicone dielectric compound.

Disconnect the cable from the negative battery terminal and remove the engine cover. On 3.9L models, also disconnect the MAP sensor.