Faulty cylinder 8 glow plug (open circuit, high resistance or shorted); Damaged, corroded or loose wiring or connector at the cylinder 8 glow plug; Wrong or non-matching glow plug fitted to cylinder 8 after a previous repair; Poor earth or supply voltage problem affecting the glow plug circuit; Faulty glow plug control module or output driver; Wiring harness damage between the control module and the cylinder 8 glow plug; Outdated or faulty control unit software where the manufacturer has issued a correction.

P06CC

Cylinder 8 Glow Plug Incorrect.

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
CC: FaultThe specific fault in that area

What it means

P06CC is the generic code for 'Cylinder 8 Glow Plug Incorrect'. The glow plug control module or engine control unit has checked the cylinder 8 glow plug, usually through its current draw, resistance or circuit feedback, and found it does not match what is expected. How the check works and what counts as 'incorrect' depends on the make, model and engine, so check the manufacturer's data for the exact setting criteria.

Symptoms

Engine management or glow plug warning light on
Harder or longer cold starting, especially in cold weather
Rough running or misfire on cold start that clears as the engine warms
White smoke from the exhaust on a cold start
Slightly higher emissions or fuel use until warm

Possible causes

Faulty cylinder 8 glow plug (open circuit, high resistance or shorted)likely
Damaged, corroded or loose wiring or connector at the cylinder 8 glow pluglikely
Wrong or non-matching glow plug fitted to cylinder 8 after a previous repairpossible
Poor earth or supply voltage problem affecting the glow plug circuitpossible
Faulty glow plug control module or output driverpossible
Wiring harness damage between the control module and the cylinder 8 glow plugrare
Outdated or faulty control unit software where the manufacturer has issued a correctionrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine temperature and battery voltage when the code was set, and look for other glow plug codes
Check the battery condition and charging voltage, as low voltage can upset glow plug diagnostics
Inspect the cylinder 8 glow plug connector and wiring for corrosion, heat damage, chafing or looseness
Check the glow plug part number against the manufacturer's specification for that engine
Measure the cylinder 8 glow plug resistance or current draw and compare it with the specification and the other glow plugs
Check the supply, earth and signal wiring for continuity and shorts between the control module and the glow plug
Use a scan tool to run the glow plug output test and watch the live data, following the manufacturer's procedure for your engine
Check for any manufacturer service bulletins or software updates relating to this code on your model

How to fix

Replace the cylinder 8 glow plug, and consider replacing the set if they are all of similar age and mileage
Repair or replace damaged wiring, terminals or the connector
Fit the correct specification glow plug if the wrong type has been installed
Repair poor earth or supply connections and correct any charging or battery problem
Replace the glow plug control module only if testing shows the module is faulty
Update the control unit software only if the manufacturer lists it as a fix for this fault

Can I keep driving?

Low severity

The car can normally be driven, but cold starting may suffer and the fault could worsen, so book it in soon. Take care when removing glow plugs, as a seized plug can snap and cause further work.

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