P0021: Camshaft A timing over-advanced (bank 2)

What P0021 means

The ECU compares the real camshaft position, read by a sensor, with the position it has requested from the variable timing system. If the camshaft stays more advanced than requested for a while, this code is stored. Most often the actuator cannot move properly because of low or dirty oil or a sticking oil control solenoid. Camshaft A is usually the intake camshaft, although each manufacturer defines it, and bank 2 is the side of the engine opposite cylinder 1 (only found on V or flat engines).

Most common causes

• Low oil level or oil of the wrong viscosity
• Old or dirty oil clogging the solenoid or its mesh filter
• Sticking variable timing oil control solenoid
• Worn or seized cam phaser (the adjustable camshaft pulley)
• Stretched timing chain or belt, or a jumped tooth
• Camshaft position sensor giving a false reading

Symptoms

• Engine warning light on
• Unstable idle or engine stalling
• Hesitation or lack of power
• Harder starting
• Higher fuel consumption

Can you drive with P0021?

With care You can drive gently, but do not leave it: if the cause is the timing chain or low oil, the damage can get worse.

How to check it

Check the oil level on the dipstick first and when it was last changed. With a scan tool, compare desired and actual camshaft angle in live data: if the actual value does not follow the desired one, suspect the solenoid or the phaser.

How to read and clear P0021 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0021 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• P0017 Crankshaft and camshaft position mismatch (bank 1, sensor B)
• P0018 Crankshaft and camshaft position mismatch (bank 2, sensor A)
• P0019 Crankshaft and camshaft position mismatch (bank 2, sensor B)
• P0020 Camshaft A actuator control: open circuit (bank 2)
• P0022 Camshaft A timing over-retarded (bank 2)
• P0030 Oxygen sensor heater circuit fault (bank 1, sensor 1)
• P0031 Oxygen sensor heater circuit low (bank 1, sensor 1)
• P0032 Oxygen sensor heater circuit high (bank 1, sensor 1)
• P0010 Camshaft A actuator control: open circuit (bank 1)
• P0011 Camshaft A timing over-advanced (bank 1)
• P0012 Camshaft A timing over-retarded (bank 1)
• P0013 Camshaft B actuator control: open circuit (bank 1)

P0021 is a generic code, so it means the same on any make, for example on Abarth, Citroën, Cupra, Hyundai, Mini, Seat. See what Final OBD does on your car in makes and models.