P0029: Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 2)
The exhaust camshaft oil control solenoid on bank 2 does not work as expected.
High risk
Usually drivable, but power and idle may suffer. Have it checked soon.
Short answer · Can I keep driving with P0029?
Usually yes. The engine may idle roughly and feel weaker. Check the oil level and have the solenoid checked soon.
What does P0029 mean?
Code P0029 means the engine control unit sees that the oil control solenoid of the exhaust camshaft on bank 2 is out of its expected range: its electrical values do not fit, or the camshaft does not follow when the solenoid is switched. A sticking or clogged solenoid, low or dirty oil, a fault in the wiring or a worn camshaft adjuster are typical causes.
What the car does when the code is set
The check engine light comes on. The engine may idle roughly, lose power or use more fuel, because the valve timing is not where the engine control unit wants it. Some engines lock the camshaft adjuster in a default position.
How the system works
Variable valve timing lets the engine change when the valves open and close. A camshaft adjuster (phaser) on the end of the camshaft turns it a few degrees relative to the sprocket, driven by engine oil that an oil control valve directs to one side or the other. The engine control unit commands a target angle, then measures the real angle by comparing the camshaft and crankshaft sensor signals. If the measured angle differs from the target for too long, or the two signals are out of their normal relationship, it stores a code.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Sticking or clogged oil control valveSludge or debris in the valve, or a worn valve, stops it moving as commanded.
- Low or dirty engine oilVariable valve timing uses oil pressure; low level or old oil makes it slow.
- Faulty oil control valveThe solenoid that directs oil to the camshaft adjuster sticks.
- Worn camshaft adjusterThe adjuster (phaser) no longer holds its position.
- Stretched timing chain or jumped beltCamshaft and crankshaft are no longer in the correct relation.
- Sensor or reluctor wheel problemA faulty position sensor or damaged trigger wheel.
How it is diagnosed
- Check oil level and conditionTop up or change the oil with the specified grade first. This alone sometimes clears the fault.
- Compare desired and actual camshaft positionWith live data, watch whether the camshaft follows the commanded angle at idle and at higher revs.
- Test the oil control valveCheck its resistance and operation, and look for debris in its screen.
- Check the timingIf the readings point to a stretched chain, the workshop checks the timing marks or measures the offset.A worn timing chain can jump teeth and damage the engine. Do not delay the diagnosis.
Questions about P0029
Can an oil change fix P0029?
Sometimes, if old or sludged oil made the solenoid stick. If the code returns, the solenoid and its wiring are checked; the solenoid is often a separate part.
Can low oil cause this code?
Yes. Valve timing control depends on oil pressure, so low or old oil is one of the first things to check.