P06DE: Engine Oil Pressure Control Circuit Stuck On
What to do
This is the less worrying of the two oil pressure control faults. The engine is getting more oil pressure than it needs, not less, so it is not in danger — the cost is a little fuel economy and a little power.
It is still worth repairing rather than ignoring. Sustained high pressure works the oil filter harder, and a filter forced into bypass passes unfiltered oil around the engine.
Mention when the oil was last changed and what grade went in. Degraded oil leaves varnish that holds these solenoids open, and it is one of the cheapest causes to address.
If any variable valve timing or engine noise faults are stored alongside, mention that too — some engines use oil pressure to drive those systems, so they are often the same fault rather than separate ones.
What this code means
Oil pressure control is stuck on, so the pump is delivering maximum pressure continuously.
This is the safe half of the stuck pair, and saying so plainly is useful because the code sounds alarming. The engine is getting more oil pressure than it needs rather than less — so nothing is being starved, and the engine is not in danger.
What it costs is real but ordinary. Driving a pump at full displacement takes measurable power from the crankshaft, which is exactly the waste that variable pumps were introduced to eliminate. Expect slightly worse fuel consumption and marginally less power.
There are two secondary effects worth knowing.
- Cold-start pressure can be very high with thick oil, and sustained high pressure works the filter and its bypass valve harder. A filter bypassing under pressure passes unfiltered oil, which is the one route by which this fault can cause harm.
- Some engines use oil pressure for other jobs — variable valve timing, chain tensioners, cylinder deactivation — and feeding them more pressure than the strategy expects can produce odd timing or deactivation faults that look unrelated.
So a stuck-on code stored alongside a variable valve timing complaint is probably one fault, not two.
The causes are the mirror of the stuck-off case: a solenoid held on by varnish or debris, a short to voltage keeping it energised, or a driver failed on. Degraded oil is again a genuine and cheap-to-fix cause.
Likely causes
Start here
- Faulty oil pressure control solenoid · moderate
- Incorrect oil grade or degraded oil · easy
Less common
- Wiring shorted to voltage · moderate
- Stuck oil pressure relief valve · specialist
Rare
- Failed control module output driver · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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