Common Symptoms
- Hard starting or extended cranking in cold weather
- White or gray smoke from exhaust on cold start
- Engine runs rough or misfires until warmed up
- Check engine light illuminated
- Glow plug indicator light stays on or flashes
- Excessive engine noise or knocking during cold start
Most Likely Root Causes
- Failed glow plug relay or control module
- Damaged or corroded wiring harness to glow plugs
- Failed individual glow plugs in circuit B
- Corroded or loose glow plug connector terminals
- Blown fuse in glow plug control circuit
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Component Location
Glow plug control relay or module is typically mounted on the firewall, fender well, or near the engine control module.
Manufacturer Notes
Some diesel engines use banked glow plug control where circuit B typically controls cylinders on one side or specific cylinder groups.
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