P06FA
Glow Plug Control Module 2 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
- FA
- FaultThe specific fault in that area
What it means
P06FA means the engine control unit has judged that glow plug control module 2 is not performing as expected. It usually sets when the module's feedback, diagnostic status or glow plug output does not match what the control unit commanded. Which glow plugs the second module controls depends on the engine, so check the manufacturer data for the model.
Symptoms
- Engine management warning light on
- Hard or slow starting when cold
- White smoke or rough running for the first few minutes after a cold start
- Glow plug warning light flashing or staying on
- Increased diesel knock at idle when cold
- Other glow plug circuit codes stored alongside it
Possible causes
- Wiring or connector fault on the module's power, earth or control circuits, such as corrosion, chafing or a loose pinlikely
- Low battery voltage or poor battery terminal or earth connections upsetting the module's supplylikely
- One or more glow plugs controlled by module 2 have failed or have high resistancelikely
- Glow plug control module 2 has failed internallypossible
- Blown fuse or faulty relay or power feed to the modulepossible
- Communication fault between the module and the engine control unit, for example a data line problempossible
- Outdated control unit software that is a known cause for this fault on certain enginesrare
How to diagnose
- Read all stored and pending codes and record the freeze frame data, noting any other glow plug, communication or low voltage codes.
- Check battery condition and charging voltage, and inspect the battery terminals and main earth connections.
- Visually inspect the module, its connectors, wiring and fuses for corrosion, heat damage, water ingress or chafing.
- Check the module's power feed, earth and control signal against the manufacturer's wiring diagram, including a voltage drop test under load.
- Use live data or an active test to see whether module 2 reports its status and commands the glow plugs on.
- Measure the resistance and current draw of each glow plug on module 2's circuit and compare with the manufacturer's specification.
- Check the data communication lines between the module and the engine control unit for faults.
- Check for a manufacturer software update or technical bulletin for this engine, and confirm the module is correctly coded if it has been replaced.
How to fix
- Repair or replace damaged wiring, connectors or terminals, and clean up poor earth connections.
- Charge or replace a weak battery and correct any charging system fault.
- Replace failed glow plugs, following the manufacturer's tightening procedure and replacing the full set if the engine's guidance recommends it.
- Replace a blown fuse or faulty relay only after finding what caused it to fail.
- Replace glow plug control module 2 if it fails testing, then code or adapt it as the manufacturer requires.
- Apply a manufacturer software update only if one is published for this fault on the vehicle.
Can I keep driving?
Medium severity
The car can usually be driven short term, but cold starting may be poor and emissions and smoke may be higher until it is fixed. Get it checked soon, because a failing module or glow plugs can cause further faults and a no-start in cold weather.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.