P06F8 code meaning
Glow Plug Control Module 2 Control Circuit High
Powertrain system Generic code P06xx codes Check engine light
What P06F8 means
P06F8 means the command line from the engine module to glow plug control module 2 is too high, typically shorted to positive – the counterpart of P0384 for module 1. Note that Ford's 2023 diesels use P0384 differently, for the supply voltage of the glow module (below 6.5 V or above 16.5 V); in J2012 that is P052F, and for module 2 P06F9. No manufacturer document available to us uses a second glow module – Ford's and GM's V8 diesels drive all eight plugs from one; the code suits systems with one module per cylinder bank. The description follows module 1 (P0384). An open line is P06F6, a short to ground P06F7. The plugs of module 2 then heat poorly or not at all, typically on one bank.
P06F8 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P06F8
- Check engine light, possibly glow plug/wait-to-start lamp
- Hard cold start, long cranking in frost
- Rough cold idle and white smoke, often one cylinder bank only
- Usually no symptoms when warm
Common causes of P06F8
- Most likelyCommand line shorted to positive or supply
- PossibleCorrosion in the connector bridging to a B+ pin
- Less likelyEngine module driver shorted
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Glow plug control module 2Module wiringEngine control module
What each part of P06F8 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| F8 | The exact fault in that area. |
What to do next
- Note P06F8 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P06F8
What does P06F8 mean?
P06F8 means "Glow Plug Control Module 2 Control Circuit High". P06F8 means the command line from the engine module to glow plug control module 2 is too high, typically shorted to positive – the counterpart of P0384 for module 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P06F8?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P06F8 fail an emissions test?
Yes, it can. P06F8 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P06F8 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P06F8 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.