What it means
A fault has been detected involving Glow Plug Control Module 2. The code alone does not identify the failed component or establish that the engine has two glow-plug banks.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Glow plug control module 2 manages diesel-engine preheating for the circuit or group identified as module 2; the code does not establish that the engine has two banks. The engine controller detects a fault involving this module, but P06F5 alone does not say whether the module, its power, ground, wiring, or connected glow plugs are responsible.
Common causes
Most likely first.
- Glow plug control module 2 internal fault
- Module power supply or ground problem
- Damaged wiring or connector
Symptoms
- Glow plug warning light on (often orange coil symbol)
- Hard cold start or no start in cold weather
- White smoke from exhaust during warm-up
How to diagnose it
- Record freeze-frame data and scan for related glow-plug and module codes to see whether the fault is isolated to module 2 or part of a wider supply problem.
- Inspect module 2's connector and nearby harness for corrosion, loose pins, heat damage, or chafing.
- Check battery condition and verify module 2 power and ground connections under the manufacturer's diagnostic procedure.
- Compare module 2's commanded preheating operation with available live data or output tests, and note whether cold-start symptoms occur.
- Test the module 2 control wiring and associated glow-plug circuits against the wiring diagram and manufacturer's specification before condemning the module.
Common fixes
- Clean and secure module 2 power, ground, or connector connections.
- Repair damaged wiring or connector terminals in the module 2 circuit.
- Replace failed glow plugs in the circuit controlled by module 2 if testing identifies them.
- Replace glow plug control module 2 if its supply, wiring, and connected loads test correctly but it still fails.
Can I keep driving?
If the engine starts and runs normally, driving is generally possible, but cold starts may become difficult and can produce white smoke during warm-up. Avoid repeated prolonged cranking, especially in cold weather.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.