What it means
Same as P05D8 with the control line shorted to supply. 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 PCV regulator valve controls crankcase ventilation flow, and the engine control module monitors the valve's electrical control circuit. This code sets when the control line is driven higher than expected, often because it is shorted to a supply voltage.
Common causes
Most likely first.
- Control line shorted to supply
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light may illuminate
- Crankcase ventilation or emissions fault may be indicated
How to diagnose it
- Review freeze-frame data and PCV-related live data to see when the fault occurred and whether the valve command or feedback is abnormal.
- Inspect the PCV regulator valve connector and harness for pinched or rubbed wiring, moisture, corrosion, or backed-out pins.
- With the circuit monitored, gently move the harness to check whether the high reading or fault status changes.
- Use the vehicle wiring diagram to check whether the control wire is shorted to a supply circuit, paying particular attention to pinched sections near powered wiring.
- If the harness and terminals check out, test the PCV regulator valve and control-module circuit using the manufacturer's procedure.
Common fixes
- Repair pinched or chafed control-wire insulation and route it clear of supply wiring.
- Clean or replace corroded terminals and repair connector seals.
- Reseat or repair a pushed-back connector pin.
- Replace the PCV regulator valve if testing confirms an internal fault.
Can I keep driving?
If the engine runs normally and no other warning appears, a short trip for diagnosis is usually reasonable. Avoid extended driving if crankcase ventilation is not operating correctly, as pressure or emissions problems may develop.
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.