Open circuit or high resistance in the cylinder 12 glow plug wiring or connector, such as corrosion or a loose terminal; Failed cylinder 12 glow plug with internal short or fault pulling the circuit low; Wiring chafed and shorted to earth between the glow plug control module and the glow plug; Faulty glow plug control module or driver output stage for that cylinder; Low battery voltage or poor power or earth supply to the glow plug control module; Fault in the engine control unit itself or its software.

P06E2

Cylinder 12 Glow Plug Control Circuit Low.

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
E2: FaultThe specific fault in that area

What it means

P06E2 is a generic powertrain code meaning the engine control unit has detected a low signal in the control circuit for the cylinder 12 glow plug. The control unit monitors the voltage or current on the glow plug driver output and sets the code when it reads lower than expected for the commanded state. Cylinder 12 means this is a large engine, typically a V12 diesel, so the exact circuit layout and the glow plug control arrangement depend on the model and engine.

Symptoms

Engine management or glow plug warning light on
Hard starting or extended cranking in cold weather
White smoke on cold start
Rough running or misfire on a cold engine
Increased emissions or fuel consumption until warmed up

Possible causes

Open circuit or high resistance in the cylinder 12 glow plug wiring or connector, such as corrosion or a loose terminallikely
Failed cylinder 12 glow plug with internal short or fault pulling the circuit lowlikely
Wiring chafed and shorted to earth between the glow plug control module and the glow plugpossible
Faulty glow plug control module or driver output stage for that cylinderpossible
Low battery voltage or poor power or earth supply to the glow plug control modulepossible
Fault in the engine control unit itself or its softwarerare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine temperature and battery voltage when the fault set, and check for other glow plug codes.
Check the battery condition and charging voltage, as low voltage can upset glow plug circuit monitoring.
Inspect the glow plug control module, its connectors and the cylinder 12 glow plug wiring for damage, corrosion, heat damage, chafing or loose terminals.
Check the relevant fuses and the power and earth supplies to the glow plug control module using the manufacturer wiring diagram.
Measure the cylinder 12 glow plug resistance and compare with the manufacturer specification, as the procedure varies by engine.
Test the wiring between the module and the glow plug for continuity and short to earth with the connectors disconnected.
Use a scan tool with live data or actuator tests, if supported, to command the glow plugs and check the cylinder 12 output and current.
Clear the code and retest to see whether it returns, after repairs.

How to fix

Repair or replace damaged wiring, and clean or renew corroded connectors or terminals in the cylinder 12 glow plug circuit.
Replace the cylinder 12 glow plug if it is out of specification, following the correct torque and removal procedure for the engine.
Repair any short to earth found in the harness.
Replace the glow plug control module if the supplies and wiring are good and the driver output is confirmed faulty.
Restore battery health or repair the power and earth supply faults affecting the module.

Can I keep driving?

Low severity

The car can normally be driven, but cold starting may be poor and the engine may run roughly until warm. Book it in soon, especially before cold weather, and avoid repeated long cranking.

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