Short to voltage in the cylinder 5 glow plug control wiring or connector; Faulty glow plug control module or driver output; Faulty cylinder 5 glow plug with internal fault affecting the circuit; Corroded, damaged or loose connector terminals at the glow plug or control module; Chafed harness touching a live feed or power supply wire; Fault in the engine control unit itself or outdated software where a known issue is documented for the model.

P067D

Cylinder 5 Glow Plug Control Circuit High.

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
7D: FaultThe specific fault in that area

What it means

P067D means the engine control unit has detected a high voltage or short to voltage fault in the control circuit for the cylinder 5 glow plug. The unit monitors the output that switches the glow plug and sets the code when the circuit reads higher than expected for the commanded state. Cylinder numbering and glow plug control layout vary by engine, so check the specific model.

Symptoms

Engine management or glow plug warning light on
Hard starting or extended cranking in cold weather
Rough running or misfire on cold start
White smoke from the exhaust on cold start
Slightly increased fuel consumption or noisy idle until warm
No noticeable symptoms in warm conditions

Possible causes

Short to voltage in the cylinder 5 glow plug control wiring or connectorlikely
Faulty glow plug control module or driver outputlikely
Faulty cylinder 5 glow plug with internal fault affecting the circuitpossible
Corroded, damaged or loose connector terminals at the glow plug or control modulepossible
Chafed harness touching a live feed or power supply wirepossible
Fault in the engine control unit itself or outdated software where a known issue is documented for the modelrare

How to diagnose

Read all stored and pending codes and note freeze frame data, including engine temperature and battery voltage
Check for other glow plug circuit codes on different cylinders, which may point to a shared module or supply fault
Test battery condition and charging voltage, as low or unstable voltage can upset glow plug diagnostics
Visually inspect the glow plug wiring, connectors and harness routing near cylinder 5 for chafing, heat damage, corrosion or water ingress
Check the glow plug control module connector and supply and earth connections for security and corrosion
Measure the cylinder 5 glow plug resistance and compare it with the manufacturer's specification
With the circuit disconnected, test the control wire for short to voltage and continuity using the wiring diagram for the specific engine
Command the glow plugs on and off with a diagnostic scan tool and check the live data and output behaviour of cylinder 5

How to fix

Repair or replace damaged wiring and fix any short to voltage in the cylinder 5 control circuit
Clean or replace corroded or damaged connectors and terminals
Replace the cylinder 5 glow plug if it tests out of specification
Replace the glow plug control module if the output is faulty and the wiring tests good
Apply a manufacturer software update only if an outdated calibration is a documented cause for that model

Can I keep driving?

Low severity

The car can normally be driven, but cold starting may be poor and the fault may worsen in cold weather. Book it in soon, and avoid repeated long cranking.

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