Generic Diesel Fault Code
Free · no signupP0672
Extended Cold Crank / White Smoke / Rough Idle
System
Starting / Pre-Heat
Symptom
Extended Cold Crank / White Smoke / Rough Idle
Diagnosis & fix steps
LOGIC: Cylinder 2 Glow Plug Circuit / Open.
ACTION: Disconnect the glow plug harness connector at Cylinder 2. Measure internal resistance between the glow plug terminal tip and engine cylinder head ground (spec: ~0.5–2.0Ω cold). If open/high resistance, replace glow plug. If resistance passes, test circuit continuity and voltage drop back to the Glow Plug Control Module (GPCM).
Red Seal field insights
Thermal Element Failure: The GPCM monitors current draw per cylinder during pre-heat and post-heat cycles. Carbon fouling, thermal cycling, and tip oxidation cause the internal heating element filament to fracture, resulting in an open circuit.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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