P2090: Camshaft actuator B control circuit low (bank 1)

What P2090 means

Many engines turn the camshaft slightly to adjust valve timing as you drive, using a solenoid controlled by the ECU. This code means the electrical signal for that solenoid (actuator B, usually the exhaust camshaft) on bank 1 is below what it should be. It is almost always an electrical fault. Which camshaft counts as B is up to each manufacturer.

Most common causes

• Loose, dirty or corroded connector on the camshaft solenoid
• A wire in the circuit chafed through or shorted to ground
• The variable valve timing solenoid itself, with a failed coil
• Very dirty oil or a low oil level making the solenoid work poorly
• A fault in the engine ECU, which is uncommon

Symptoms

• Engine warning light on
• Rough idle or some loss of power
• Slightly higher fuel consumption
• The engine may go into limp mode

Can you drive with P2090?

With care You can drive, as the ECU usually locks the timing in a fixed position. The engine will be down on power, so have it checked soon.

How to check it

Check the oil level and condition first. With the engine off, make sure the solenoid connector is fully seated and free of green corrosion.

How to read and clear P2090 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 P2090 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

• P2081 Exhaust gas temperature sensor circuit intermittent (bank 1, sensor 1)
• P2084 Exhaust gas temperature sensor reading out of range (bank 1, sensor 2)
• P2088 Camshaft position actuator A control circuit low (bank 1)
• P2089 Camshaft actuator A control circuit high (bank 1)
• P2091 Camshaft actuator B control circuit high (bank 1)
• P2096 Post-catalyst fuel trim system too lean (bank 1)
• P2097 Post-catalyst fuel trim system too rich (bank 1)
• P2098 Post-catalyst fuel trim system too lean (bank 2)
• P2002 Diesel particulate filter efficiency below threshold (bank 1)
• P2003 Diesel particulate filter efficiency below threshold (bank 2)
• P2004 Intake manifold runner control stuck open (bank 1)
• P2005 Intake manifold runner control stuck open (bank 2)

P2090 is a generic code, so it means the same on any make, for example on Audi, BMW, Fiat, Mazda, Peugeot, Volkswagen. See what Final OBD does on your car in makes and models.