Glow plug for cylinder 11 worn or degraded, with resistance out of specification; Corroded, loose or damaged wiring or connector at the cylinder 11 glow plug; Wrong glow plug type fitted, or one with a different resistance to the original; High resistance in the power feed, earth or fusing to the glow plug circuit; Fault in the glow plug control module or its output stage; Cylinder numbering misidentified, so the actual fault is on a different plug.

P06CF

Cylinder 11 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
CF: FaultThe specific fault in that area

What it means

P06CF is a generic code meaning the glow plug control module has judged the glow plug serving cylinder 11 to be incorrect. In practice the control unit has seen current, resistance or feedback from that glow plug that does not match what it expects. How it measures this, and the exact limits, vary by manufacturer and engine. Cylinder 11 only exists on large engines, so confirm the cylinder numbering for the vehicle.

Symptoms

Engine management or glow plug warning light on
Harder starting or longer cranking on cold mornings
Rough running or a misfire for the first minutes after a cold start
White or grey smoke and a diesel smell at start-up
Higher emissions or poor cold-start performance

Possible causes

Glow plug for cylinder 11 worn or degraded, with resistance out of specificationlikely
Corroded, loose or damaged wiring or connector at the cylinder 11 glow pluglikely
Wrong glow plug type fitted, or one with a different resistance to the originalpossible
High resistance in the power feed, earth or fusing to the glow plug circuitpossible
Fault in the glow plug control module or its output stagerare
Cylinder numbering misidentified, so the actual fault is on a different plugpossible

How to diagnose

Read all stored and pending codes and the freeze frame data, and note any other glow plug codes or related faults
Check the manufacturer's cylinder numbering for the engine so you know exactly which glow plug is cylinder 11
Visually inspect the cylinder 11 glow plug wiring and connector for damage, corrosion, heat damage and a secure fit
Check the battery condition and charging voltage, as low voltage can affect glow plug readings
Measure the glow plug resistance and compare it with the manufacturer's specification, and compare it against the other plugs
Check the supply voltage, earth and fuses for the glow plug circuit, using the wiring diagram for the model
Use a scan tool to run the glow plug activation test if the vehicle supports it, and watch current or feedback values for cylinder 11
Check the part number of the fitted glow plug against the correct one for the engine

How to fix

Replace the cylinder 11 glow plug with the correct specification part, and consider replacing the set if they are of similar age
Repair or replace damaged wiring, terminals or connectors at the glow plug
Clean and tighten corroded power or earth connections and repair any high-resistance fault in the feed
Fit the correct glow plug where the wrong type was installed
Replace the glow plug control module only after the plugs, wiring and supply have been proven good

Can I keep driving?

Low severity

The car can usually be driven while you book it in, as the fault mainly affects cold starting and emissions. Get it checked soon, because starting may get worse in cold weather and a seized or broken glow plug can cause further problems.

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