What it means
Same as P06F6 with the control line shorted to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The engine controller sends a command to glow plug control module 2 over a control circuit. P06F7 sets when that control line is held too low, typically because it is shorted to ground or has a wiring or connector fault that pulls the signal down.
Common causes
Most likely first.
- Control line shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
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 and related glow-plug codes, then check live or commanded module 2 status to confirm the control fault is current.
- Inspect the module 2 connector and control-wire route for chafing, exposed conductor, corrosion, or trapped wiring.
- Check for a control wire short to ground using the wiring diagram and the manufacturer's specified test method.
- Move the harness carefully during the circuit test to find an intermittent ground contact, and inspect connector pins for corrosion or poor contact.
- If the control wire is not grounded and connectors are sound, test module 2 and the engine-controller output as directed by the manufacturer.
Common fixes
- Repair insulation damage where the module 2 control line is touching ground.
- Clean or replace corroded terminals and restore the connector seal.
- Replace damaged control-circuit wiring or connector pigtails.
- Replace module 2 only if the low control signal persists with the external circuit verified.
Can I keep driving?
Driving is usually possible if the engine runs normally, but cold starts may be hard and warm-up smoke may increase. Avoid repeated long cranking and get the circuit repaired before relying on the vehicle 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.