What it means
Glow Plug Control Module 2 Performance: the component is electrically intact but its response does not match the command. This affects diesel cold-start preheating.
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 preheating in response to commands from the engine controller. P06FA sets when the module's response does not match the commanded operation, even if the circuit is not simply open or shorted.
Common causes
Most likely first.
- Glow plug control module 2 not responding as commanded
- Module power or ground problem
- Wiring or connector fault
- Control module internal fault
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
- Capture freeze-frame data and compare the commanded and reported module 2 status, including any related glow-plug codes.
- Inspect module 2 connectors and wiring for corrosion, loose terminals, chafing, or heat damage.
- Verify module 2 power and ground during a preheating command against the manufacturer's specification.
- Use the vehicle's supported output test or live data to check whether module 2 responds consistently to a command.
- Test the module 2 control circuit and associated glow-plug load circuits before concluding that the module itself has a performance fault.
Common fixes
- Clean and secure module 2 connectors and power or ground connections.
- Repair damaged control wiring or connector terminals affecting module 2 response.
- Replace a failed glow plug or repair its circuit if testing shows an abnormal load.
- Replace glow plug control module 2 if supply, wiring, and loads are sound but its commanded response remains incorrect.
Can I keep driving?
The engine may remain drivable, but preheating can be ineffective, causing hard cold starts and white smoke during warm-up. Avoid repeated cranking and fix the fault before depending on reliable cold starting.
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.