Failed cylinder 2 glow plug with an open internal element; Corroded, loose or damaged connector or terminal at the cylinder 2 glow plug; Damaged, chafed or broken wiring between the glow plug control module and the cylinder 2 glow plug; Blown fuse or fusible link in the glow plug supply; Faulty glow plug control module or driver stage for cylinder 2; Poor earth or power supply connection affecting the glow plug circuit; Fault in the engine control unit.

P0672

Cylinder 2 Glow Plug Circuit/Open.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
6: AreaComputer and output circuits
72: FaultThe specific fault in that area

What it means

P0672 is the generic code for an open circuit in the cylinder 2 glow plug circuit. The engine control unit (or glow plug control module) monitors the glow plug circuit and found no current flow or a missing signal where it expected one, so it set the fault. This applies to diesel engines, and how the glow plugs are controlled and monitored varies by model and engine.

Symptoms

Hard starting on cold mornings, especially in low temperatures
Extra white or grey smoke on start-up until the engine warms
Rough or uneven running and misfire for the first minute after a cold start
Glow plug or engine management warning light on the dashboard
Slightly higher fuel consumption when cold
No noticeable symptoms in warm weather

Possible causes

Failed cylinder 2 glow plug with an open internal elementlikely
Corroded, loose or damaged connector or terminal at the cylinder 2 glow pluglikely
Damaged, chafed or broken wiring between the glow plug control module and the cylinder 2 glow plugpossible
Blown fuse or fusible link in the glow plug supplypossible
Faulty glow plug control module or driver stage for cylinder 2possible
Poor earth or power supply connection affecting the glow plug circuitrare
Fault in the engine control unitrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting whether other glow plug codes are present, which points towards a shared supply or module fault
Visually inspect the glow plug wiring, connector and terminal at cylinder 2 for corrosion, heat damage, chafing or looseness
Check the glow plug fuse and the supply and earth connections for the glow plug system, following the manufacturer's wiring information
With the glow plug disconnected, measure its resistance with a multimeter and compare with the specification for the engine; an open reading confirms a failed plug
Check for supply voltage and the control signal at the cylinder 2 connector during the glow cycle, following model-specific procedure
Wiggle-test the harness while monitoring live data or measuring continuity to find intermittent breaks
If the plug and wiring are good, test the glow plug control module output for cylinder 2 according to the manufacturer's procedure

How to fix

Replace the failed cylinder 2 glow plug, using the correct specification and torque, and take care as old plugs can seize or snap
Clean or replace the corroded or damaged connector and terminal
Repair or replace the damaged section of wiring, restoring proper insulation and routing
Replace the blown fuse only after finding out why it failed
Replace the glow plug control module if its output for cylinder 2 is confirmed faulty
Clear the code after repair and confirm it does not return after a cold start test

Can I keep driving?

Low severity

The car can normally be driven, but cold starting may be poor and the engine may run roughly until warm. Book it in soon, and avoid repeated cold starts in winter until repaired.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.