Skip the auto shop - Our mechanics make house calls

P0021 OBD-II Trouble Code: Camshaft Position A - Timing Over-Advanced or System Performance (Bank 2)

Check Engine Light

P0021 code definition

Camshaft Position A - Timing Over-Advanced or System Performance (Bank 2)

What the P0021 code means

P0021 is the OBD-II generic code indicating that the Engine Control Module (ECM) has determined that the bank 2 intake camshaft is more advanced than what the ECM has commanded it to be. This over advanced condition could be during advancing, or retarding of the camshaft timing.

What causes the P0021 code?

  • The camshaft is more advanced than the ECM has commanded it to advance.

  • The camshaft is more advanced when it has been commanded to retard to a lower timing level.

  • The Oil Control Valve (OCV) connected to the bank 2 camshaft may be stuck or have clogged oil passages.

  • The oil is too thick, causing the passages to become clogged. This can be from the wrong oil or lack of oil changes.

  • The camshaft phaser is stuck in the advanced position.

What are the symptoms of the P0021 code?

  • The ECM will turn on the Check Engine Light.

  • The engine may idle normally but can hesitate or stall on acceleration.

  • A reduction in fuel mileage may happen due to the camshafts not being at an optimal position.

  • The engine emissions may exceed federal levels.

Note: The symptoms may change depending on the camshaft timing positions when the camshaft stopped advancing or retarding.

How does a mechanic diagnose the P0021 code?

  • Visually inspects for damaged wiring or connectors

  • Checks the engine for sludge and for the engine to be full of clean engine oil with the correct viscosity

  • Scans and documents the codes then views the freeze frame data to see when the code was set

  • Clears the OBD-II fault codes and retests the vehicle to see if the P0021 code comes back

  • Performs the manufacturer's pinpoint tests for the P0021 code

Note: The manufacturer's pinpoint test will be different for different engines and year of manufacturer.

Common mistakes when diagnosing the P0021 code

Follow these simple guidelines to help prevent misdiagnosis:

  • Do a visual inspection for problems, like checking to see if all electrical connectors are connected, or harness is damaged.

  • Check engine oil to see if it is full, clean and of the correct viscosity.

  • Verify the failure code is active by clearing and retesting the code.

  • Follow pinpoint tests step-by-step without skipping any steps.

How serious is the P0021 code?

  • The engine may run erratically and have various drive complaints that could cause unsafe driving conditions if the engine hesitates or stalls.

  • The fuel consumption may increase and carbon fouling of engine components may occur.

What repairs can fix the P0021 code?

  • Clearing the Check Engine Light codes and road testing to verify the code

  • Changing the oil and filter to the proper oil viscosity for the engine specifications

  • Repairing or replacing the wiring to the camshaft oil control valve for bank 2 intake camshaft

  • Replacing the camshaft oil control valve for bank 2 intake camshaft

  • Checking the timing chain and camshaft phasers

Additional comments for consideration regarding the P0021 code

The engine oil passages through the camshafts; the oil control valves are of small size and require only the manufacturer's recommended oil viscosity to be used. If the oil is sludged up or an oil with a higher viscosity is in the engine, then it could cause the camshaft VVT to not work as designed.

Need help with a P0021 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

How Long Does a Throttle Return Spring Last?
Not all vehicles on the road feature an electronic throttle control (ETC), which is also called drive-by-wire. For vehicles that don't offer this system, they have a throttle cable instead that...
How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...


Related questions

Q: My truck is losing power on take off and throwing multiple codes

Hello. The codes listed are indicative of lean conditions on both banks A and B, as well as issues with the camshaft position sensor for circuit B. A lean condition at both banks can be caused by many things. A...

Q: Service engine light

The service engine light or check engine light coming on in cooler temperature could be you gas cap seal but you would need to have the computer scanned first to see if you have codes in memory of the computer...

Q: I had my ECS replaceed and my TPS and the code for TPS was gone but the ECS code came on after 5 miles is it possible the new one

There is a possibility the new module is faulty, but there may be something else going on with the car as well. Wiring can be an issue with these vehicle so consider hiring an experienced technician like one from YourMechanic...