How to Replace a 6.0 Powerstroke Glow Plug Control Module

Confirm the part and repair scope

The 6.0L diesel was used in 2003 through 2007 Super Duty pickups and chassis cabs, 2003 through 2005 Excursions and 2004 through 2010 E-Series vans. Mounting location, harness routing and bracket shape differ between these body styles. Order the module by VIN or by the number printed on the original module label, not by engine size alone. The engine is a V8 with one glow plug per cylinder, so the module drives eight separate circuits. It also has power, ground, and command and feedback lines to the powertrain control module.

Typical trouble codes are P0670 for the module control circuit, P0671 through P0678 for individual cylinder glow plug circuits, and P0683 for the module-to-PCM communication circuit. A single cylinder code usually points to that glow plug, its harness or the connector under the valve cover, which is a known weak point on this engine. It rarely means the module has failed. Several cylinder codes at once, a P0670 or P0683, or no power reaching any plug during a commanded glow cycle make the module more likely. Before buying a part, check the module's main power feed, ground and command signal. Then measure the resistance of each glow plug circuit through the harness connector and compare the cylinders against the value in the service information.

Also rule out problems that mimic weak glow. A hard start on a 6.0 can come from low fuel pressure, a restricted fuel filter, a weak fuel pump in the frame-mounted fuel conditioning module, low FICM voltage, or injector and high-pressure oil faults. The fuel injection control module is a separate part from the glow plug module, and the two are often confused. Fuel additives can help with gelling in cold weather, but they will not repair an electrical fault in the glow circuit.

Prepare tools and safe access

You need basic metric hand tools, a digital multimeter, dielectric grease, and contact cleaner or a small terminal brush. You also need a scan tool that reads Ford diesel codes, ideally one that can display or command glow plug status. A creeper and good lighting help, because on Super Duty pickups the module is typically mounted on the driver-side frame rail, where road spray and salt collect. Look up the mounting location, fastener torque and connector release method for your body style in the factory service information instead of guessing. Vans and Excursions are packaged differently.

Park on level ground, set the parking brake and chock the wheels. If you need more clearance, support the vehicle on rated jack stands, never on a jack alone. This engine uses two batteries, so disconnect the negative cable from both before touching the module connectors. The glow circuit carries high current, and an accidental short can burn wiring. No fuel system work is needed for this repair, so do not open fuel lines or try to relieve fuel or oil pressure. If you are not comfortable working under a vehicle or testing circuits with a meter, leave the diagnosis and replacement to a diesel technician.

Remove without avoidable damage

Photograph the module and its connectors first so you can match the routing later. Release the locking tabs or levers and pull each connector straight off. Prying at an angle can crack the housings or bend terminals. Corroded connectors may be stiff, so work them gently and support the harness instead of pulling on the wires. Inspect each terminal as it comes free. Green corrosion, burned or loose pins, or melted plastic mean the harness needs repair, because a new module plugged into a damaged connector can fail the same way.

Remove the mounting fasteners and lower the module out. Note how it sits against the frame rail, and check the service information for whether the mounting points serve as a ground. Clean rust and debris from the mounting area. Work around the nearby fuel conditioning module and fuel lines without bending or loosening them. If you disturb any fuel fitting, do a leak check before closing the job.

Install and restore the system

Compare the new module with the old one before mounting it. The housing, bracket, connector count and keying should match exactly. Mount it in the original orientation and tighten the fasteners to the torque in the service information. Apply a light film of dielectric grease to the connector seals without packing the terminal cavities. Push each connector home until the lock clicks, and engage any secondary locks. Route and secure the harness away from exhaust heat, sharp frame edges and the driveshaft, and replace any broken clips.

Reconnect the negative cables on both batteries. Check the service information or the part supplier's instructions to see whether the replacement needs programming or a relearn. Do not assume it does or does not. Clear stored glow plug codes with the scan tool only after the repair is complete, so you can tell whether any of them return.

Check the completed work

Turn the key on with the engine off and confirm the module receives a glow command. If your scan tool supports it, watch the glow plug status or diagnostic data. Otherwise, measure voltage at a glow plug feed during the cycle, or use a clamp-on ammeter on the module feed or individual plug wires. The wait-to-start lamp is timed by the engine computer, so the lamp turning on does not prove the plugs are heating. Run any available self test, then recheck for codes after a few drive cycles.

The best real-world check is a cold start after the engine has sat overnight. It should crank briefly, fire on all cylinders and clear white smoke quickly. If a cylinder code returns, test that plug and its connection under the valve cover. If several codes return or the module never powers the plugs, recheck its power, ground and command circuits. If the glow circuit tests good and the engine still starts hard, move on to fuel pressure, injector or oil pressure diagnosis rather than replacing another module.