Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Glow plug system assists in providing heat required to begin combustion during engine starting at cold ambient temperatures. Glow plugs are heated before and during cranking as well as initial engine operation. PCM controls glow plug on time by monitoring coolant temperatures and glow plug voltage.
DTC will set when the following conditions are present:
- PCM has commanded glow plugs on and voltage at glow plugs is less than 4 volts.
Or
- PCM has commanded glow plugs off and voltage at glow plugs is greater than 4 volts.
Or
- PCM has commanded glow plugs on and a greater than 2 volt difference exists between glow plug voltage and ignition voltage.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.