P0672
Cylinder 2 Glow Plug Circuit
If your vehicle's onboard computer has flagged the diagnostic trouble code P0672, it refers to a detected anomaly regarding "Cylinder 2 Glow Plug Circuit". This systemic engine fault needs a targeted check before symptoms expand.
Driver's Summary
P0672 is triggered when the PCM detects an abnormal condition associated with cylinder 2 glow plug circuit. You may notice diesel engine misfires on cold start, white exhaust smoke, all of which are direct consequences of this malfunction. Low severity — the car drives normally, but the fault should be diagnosed and resolved within the next few weeks.
Symptoms
Diesel engine misfires on cold start, white exhaust smoke
Common Causes
- Failed cylinder 2 glow plug
- Broken wire to cylinder 2 glow plug
- Loose glow plug nut/connector
- Bad glow plug relay
How to Fix
- 1 Test glow plug resistance and replace
- 2 Repair broken wiring
- 3 Tighten electrical connections
- 4 Replace glow plug relay
Technical Explanation
To set P0672, the PCM samples the affected circuit multiple times per second, comparing live readings against manufacturer-programmed operating windows. A two-trip detection strategy is employed for most powertrain codes: the fault must be detected on one drive cycle, the vehicle key-cycled off, and the fault detected again on the next drive cycle before the MIL illuminates and a permanent DTC is stored. Once confirmed, the code is stored as a permanent DTC and the MIL is activated. The freeze frame snapshot — recording RPM, load, coolant temperature, and fuel trim at fault detection — is also saved and is critical for accurate diagnosis.
Is It Safe to Drive?
Immediate safety risk is low with P0672 active. The primary concern is regulatory — this fault will cause a failed emissions test — and the secondary risk is that the small root cause (failed cylinder 2 glow plug) becomes a larger problem if ignored for months.
Mechanic's Pro Tip
Before replacing any component on P0672, spend 5 minutes inspecting the wiring harness and connector first — corrosion, chafed insulation, and backed-out pins cause the majority of these faults and cost nothing to fix. Use a multimeter to measure voltage drop across the connector pins under load; anything above 0.1V indicates excessive resistance that will cause intermittent failures even after replacing the sensor.
Related Fault Codes
Frequently Asked Questions
What does OBD2 code P0672 mean?
OBD2 code P0672 refers to Cylinder 2 Glow Plug Circuit. If your vehicle's onboard computer has flagged the diagnostic trouble code P0672, it refers to a detected anomaly regarding "Cylinder 2 Glow Plug Circuit". This systemic engine fault needs a targeted check before symptoms expand.
What are the most common symptoms of DTC P0672?
Drivers experiencing code P0672 typically report: Diesel engine misfires on cold start, white exhaust smoke.
Is it safe to drive with trouble code P0672 active?
Immediate safety risk is low with P0672 active. The primary concern is regulatory — this fault will cause a failed emissions test — and the secondary risk is that the small root cause (failed cylinder 2 glow plug) becomes a larger problem if ignored for months.
How much does it cost to fix code P0672?
The estimated repair cost for P0672 ranges from $80 to $300 USD. Glow plug replacement: $80 - $200
Glow plug replacement: $80 - $200
Need Professional Diagnostic Assistance?
Always verify sensor signals and wiring integrity with an OBD2 scanner before purchasing replacement parts.
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