Faulty or high-resistance glow plugs causing abnormal current draw that the module flags as a performance fault; Wiring or connector problems on the module's power, earth, glow plug output or communication lines (corrosion, chafing, loose pins); Low battery voltage or poor charging causing the module to under-perform or report implausible values; Failed or degraded glow plug control module (internal fault or overheated output stage); Blown fuse or faulty relay in the glow plug supply circuit; Communication fault between the module and the ECU, or outdated control software where a known issue exists.

P06E5

Glow Plug Control Module 1 Performance.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
6: AreaComputer and output circuits
E5: FaultThe specific fault in that area

What it means

P06E5 is a generic code meaning the engine control unit has judged the performance of glow plug control module 1 to be outside expected limits. It usually sets when the module's feedback, diagnostic signal or glow plug output does not match what the ECU commanded. The exact test varies by model and engine, so the trigger conditions should be checked against manufacturer data.

Symptoms

Hard starting or extended cranking on a cold engine
White smoke or rough running for the first few seconds after a cold start
Glow plug or engine warning light on the dashboard
Engine running in a reduced-performance mode on some models
Higher than normal cold-start emissions or diesel knock

Possible causes

Faulty or high-resistance glow plugs causing abnormal current draw that the module flags as a performance faultlikely
Wiring or connector problems on the module's power, earth, glow plug output or communication lines (corrosion, chafing, loose pins)likely
Low battery voltage or poor charging causing the module to under-perform or report implausible valuespossible
Failed or degraded glow plug control module (internal fault or overheated output stage)possible
Blown fuse or faulty relay in the glow plug supply circuitpossible
Communication fault between the module and the ECU, or outdated control software where a known issue existsrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine temperature, battery voltage and whether the fault is intermittent or permanent
Check for related glow plug circuit, communication or battery voltage codes, as they point to the root cause
Test battery condition and charging voltage, and check the battery terminals and main earth connections
Inspect the module's wiring, connectors, fuses and relay for damage, corrosion, water ingress or heat damage
Check the supply and earth at the module's connector against the wiring diagram, including voltage drop under load
Measure glow plug resistance and current draw against the manufacturer's specification, as the procedure depends on the engine
Use live data or an output test to confirm that the module responds to ECU commands and reports sensible diagnostics
Check for manufacturer service information or software updates relating to this code on the specific model

How to fix

Repair or replace damaged wiring, terminals and connectors, and clean the earth points
Replace faulty glow plugs, usually as a full set, following the correct torque and removal procedure for the engine
Replace the fuse or relay if it has failed, after finding out why it failed
Charge or replace a weak battery and repair any charging system fault
Replace the glow plug control module only after supply, earth, wiring and glow plugs are proven good, and code or adapt it if the model requires it
Apply a manufacturer calibration update only where an outdated calibration is a documented cause

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but cold starting may get worse and the engine may enter a reduced-performance mode. Have it diagnosed soon, especially before cold weather, to avoid a no-start or further damage to the glow plug system.

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