Faulty glow plug on cylinder 6 (internal short or open); Damaged or chafed wiring in the glow plug control circuit (short to ground); Corroded or loose electrical connector at the glow plug; Failed glow plug control module (GPCM) or relay; Open circuit in the control wire between the ECM and glow plug; Poor ground connection for the glow plug circuit

DTC codes / P06xx · Computer and output circuits / P067E

P067ECylinder 6 Glow Plug Control Circuit Low

Q: What does code P067E mean?

Cylinder 6 Glow Plug Control Circuit Low. P067E indicates that the engine control module (ECM) has detected a low-voltage condition on the control circuit for cylinder 6's glow plug, which is used in diesel engines to aid cold starting. The ECM monitors the circuit and sets this code when the voltage on the control wire falls below the expected threshold, typically due to a short to ground or an open circuit.

P067E indicates that the engine control module (ECM) has detected a low-voltage condition on the control circuit for cylinder 6's glow plug, which is used in diesel engines to aid cold starting. The ECM monitors the circuit and sets this code when the voltage on the control wire falls below the expected threshold, typically due to a short to ground or an open circuit.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

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
Engine misfire or stumbling during the first few minutes of operation
Reduced fuel economy during warm-up
In severe cases, the engine may fail to start in cold weather

Common causes, most likely first

Faulty glow plug on cylinder 6 (internal short or open)
Damaged or chafed wiring in the glow plug control circuit (short to ground)
Corroded or loose electrical connector at the glow plug
Failed glow plug control module (GPCM) or relay
Open circuit in the control wire between the ECM and glow plug
Poor ground connection for the glow plug circuit

How to diagnose and fix it

Perform a visual inspection of the cylinder 6 glow plug, wiring, and connector for damage or corrosion
Use a multimeter to check the resistance of the glow plug and compare to specifications
Check for voltage on the control circuit with the key on and engine cold; verify the GPCM is commanding the glow plug on
Inspect the wiring harness for shorts to ground or open circuits, especially near hot or moving components
Test the glow plug control module or relay according to the manufacturer's procedure
Replace the faulty glow plug if resistance is out of range or it fails a bench test
Clear the code and verify the repair with a test drive, ensuring the monitor runs and the light stays off

Don't overlook the glow plug control module

A shorted glow plug can cause the control module to shut down the entire circuit, setting codes for multiple cylinders, so always check for additional glow plug codes.
The control circuit low code often results from a short to ground in the wiring, which can be caused by chafing against the engine block or exhaust manifold.
Some vehicles use a single glow plug control module that can fail intermittently, causing low voltage codes only under certain temperature conditions.
Replacing a glow plug without checking the control module can lead to repeat failures if the module is supplying incorrect voltage.
A weak battery or poor ground connection can mimic a glow plug circuit fault by causing low voltage during the glow plug's high-current draw.

Can I keep driving with P067E?

You can generally drive the vehicle, but cold starting may be difficult and prolonged driving with a faulty glow plug can lead to excessive smoke and carbon buildup. Avoid heavy loads or extended idling until the repair is made, and address the issue promptly to prevent further damage.

Tools that help

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