Failed cylinder 5 glow plug (open or shorted element); Damaged or corroded electrical connector at the glow plug; Broken or chafed wiring in the glow plug circuit; Faulty glow plug control module or relay; Poor ground connection for the glow plug circuit; Engine control module software issue or internal fault (rare)

DTC codes / P06xx · Computer and output circuits / P0675

P0675Cylinder 5 Glow Plug Circuit

Q: What does code P0675 mean?

Cylinder 5 Glow Plug Circuit. P0675 indicates that the engine control module has detected a fault in the electrical circuit for the cylinder 5 glow plug, which is used in diesel engines to warm the combustion chamber for reliable cold starts. The computer monitors the circuit for expected resistance and current draw, and when the signal falls outside the manufacturer's specified range, it sets this code and illuminates the check engine light.

P0675 indicates that the engine control module has detected a fault in the electrical circuit for the cylinder 5 glow plug, which is used in diesel engines to warm the combustion chamber for reliable cold starts. The computer monitors the circuit for expected resistance and current draw, and when the signal falls outside the manufacturer's specified range, it sets this code and illuminates the check engine light.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaComputer and output circuits

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Hard starting or rough idle when the engine is cold
Excessive white smoke from the exhaust after a cold start
Misfire or stumbling during the first few minutes of operation
Reduced fuel economy during warm-up
In severe cases, a no-start condition in cold weather

Common causes, most likely first

Failed cylinder 5 glow plug (open or shorted element)
Damaged or corroded electrical connector at the glow plug
Broken or chafed wiring in the glow plug circuit
Faulty glow plug control module or relay
Poor ground connection for the glow plug circuit
Engine control module software issue or internal fault (rare)

How to diagnose and fix it

Perform a visual inspection of the cylinder 5 glow plug, connector, and wiring for damage or corrosion
Use a scan tool to command the glow plug on and check for voltage and current draw at the plug
Measure the resistance of the glow plug with a multimeter and compare to specification
Test the glow plug control module output and verify proper operation
Check for continuity and voltage drop across the wiring and ground circuits
Replace the faulty glow plug or repair damaged wiring as needed
Clear the code and verify the repair with a cold-start test and scan tool data

Glow plug circuit faults often misdiagnosed

A glow plug that tests good when cold can still fail intermittently when hot, so resistance checks should be done both cold and after warming.
The glow plug control module may set a cylinder-specific code even when the fault lies in the shared power or ground circuit, so always check common feeds.
Corrosion inside the glow plug connector boot is a frequent cause that is easily overlooked during visual inspection.
Some vehicles use a glow plug with an integrated pressure sensor, and a fault in the sensor portion can trigger a circuit code without affecting glow function.
After replacing a glow plug, the engine control module may need to relearn the glow plug adaptation, which requires a scan tool.

Can I keep driving with P0675?

You can generally continue driving with P0675, but cold starts may be rough and white smoke may be noticeable; avoid extended idling and schedule diagnosis soon to prevent strain on the starter and battery.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.