P06FC code meaning
Glow Plug Control Module 2 to PCM Communication Circuit
Powertrain system Generic code P06xx codes Check engine light
What P06FC means
P06FC means the feedback or communication from glow plug control module 2 to the engine module is missing, or the line is open or shorted – the counterpart of P0683 for module 1. Depending on design the module reports over a single feedback wire (Bosch-type systems expect it inverse to the command line) or over the bus; GM and Ford report a lost bus link as U0106 rather than P0683. 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 (P0683). The engine module then loses the plug status reports; implausible messages are P06FD. The plugs of module 2 then heat poorly or not at all, typically on one bank.
P06FC 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 P06FC
- 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 P06FC
- Most likelyFeedback or bus line open or shorted, connector corroded
- PossibleGlow module 2 without supply (does not transmit)
- Less likelyGlow module 2 or engine module interface faulty
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 2Glow plug feedback lineEngine control module
What each part of P06FC 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. |
| FC | The exact fault in that area. |
What to do next
- Note P06FC 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 P06FC
What does P06FC mean?
P06FC means "Glow Plug Control Module 2 to PCM Communication Circuit". P06FC means the feedback or communication from glow plug control module 2 to the engine module is missing, or the line is open or shorted – the counterpart of P0683 for module 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P06FC?
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 P06FC fail an emissions test?
Yes, it can. P06FC 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 P06FC to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P06FC 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.