What it means
Same as P05E8 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 oil bypass valve control circuit carries commands or electrical current for the valve, and the control module monitors its signal level. This low-circuit code sets when the monitored line is below the expected range, often because it is shorted to ground or has a poor connection.
Common causes
Most likely first.
- Control line shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check-engine light may illuminate
- Oil temperature or engine warm-up behavior may be affected
How to diagnose it
- Record freeze-frame data and note oil-temperature behavior or warm-up symptoms associated with the fault.
- Inspect the oil bypass valve connector for moisture, corrosion, loose terminals, or pins pushed back into the connector body.
- Trace the control wiring for rubbed or crushed insulation that could let the line contact ground.
- Following the wiring diagram's isolation procedure, test the control line for a short to ground and compare results with the manufacturer's specification.
- If no harness short is present, test the valve circuit and its connections against the manufacturer's specification.
Common fixes
- Reconnect and secure a loose oil bypass valve connector.
- Clean or repair corroded or pushed-back connector terminals.
- Repair wiring where the control line is chafed or shorted to ground.
- Replace a valve that fails electrical testing.
Can I keep driving?
If there is no oil-pressure warning, unusual engine noise, or abnormal temperature behavior, limit driving and have the fault checked soon because the bypass valve may not operate as intended. Stop the engine if oil pressure drops or it overheats.
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.