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P2090 OBD-II Trouble Code: 'B' Camshaft Position Actuator Control Circuit Low Bank 1

Check Engine Light

P2090 Code Definition

The P2090 code is a generic powertrain code related to fuel and air metering and auxiliary emission controls. This code appears when the engine control module (ECM) has detected variances between camshaft B and the crankshaft at idle outside of set allowed parameters.

Codes related to the P2090 include:

What the P2090 Code Means

If a P2090 code appears, the ECM has detected variances between camshaft B and the crankshaft of 10 degrees at idle or more for more than 10 seconds.

The B camshaft is the vehicle’s rear, exhaust, or right camshaft, and Bank 1 of an engine is usually the bank that contains the engine’s number 1 cylinder. The camshaft actuator system includes four actuator solenoids, four oil control valves, and four actuators.

A vehicle’s engine control module (ECM) controls the camshaft position actuator through two circuits: a high control circuit and a low control circuit. The high control circuit carries a 12-volt pulse width modulated signal from the vehicle’s ECM to the camshaft position actuator solenoid. The low control circuit is the return circuit. The electrical signal is sent through the control circuits to the camshaft position actuator solenoids for desired camshaft timing changes.

What Causes the P2090 Code?

Several problems may cause a P2090 code including:

  • Damaged, shorted, or corroded electrical wiring, connectors, and/or circuitry
  • Damaged or defective variable valve timing (VVT) or variable camshaft timing (VCT) solenoid
  • Bad camshaft timing
  • Low oil pressure
  • Low oil levels
  • Misaligned timing belt or other components
  • Damaged or defective ECM (rare)

What are the Symptoms of the P2090 Code?

Symptoms of a P2090 code may include:

  • A Check Wngine or warning light may illuminate
  • The vehicle may not start or crank over at all
  • The vehicle may shake at idle
  • The vehicle may shake during acceleration
  • Decreased fuel efficiency
  • Overall poor engine performance

How Does a Mechanic Diagnose the P2090 Code?

A mechanic may use several methods to diagnose a P2090 trouble code, including:

  • Utilize an OBD-II scanner to check for a stored P2090 trouble code

  • Check vehicle oil level and pressure

  • Check and ensure all timing components are aligned correctly

  • Visually inspect all wiring circuitry and components for damage

  • Check and monitor crankshaft and camshaft positions with electromagnetic sensors

  • Disconnect the affected actuator from the connector and test voltage for a reference signal and ground (typically 5 volts with the key in the “on” position and the engine turned off)

  • Test for shorted terminals at the damaged or affected solenoid

  • Check all electrical circuits for continuity and resistance

  • Use an oscilloscope to test wave patterns from the sensor and check for anything outside of allowed parameters

Common Mistakes when Diagnosing the P2090 Code

A sticking camshaft actuator could be the result of dirty engine oil, so ensure your vehicle’s oil is changed regularly.

Some vehicle owners have reported a P2090 code after other repairs, such as a timing belt replacement or chain replacement. If any components in the timing system are improperly aligned, sensors or even the ECM itself can be unnecessarily blamed for the error and replaced.

How Serious is the P2090 Code?

Because a vehicle’s safe driving operation may be impacted due to faults that store a P2090 code, this is considered a potentially serious code. When this code appears, it is recommended that you have it diagnosed and repaired as soon as possible.

What Repairs can Fix the P2090 Code?

Several repairs can fix a P2090 trouble code and include:

  • Repair or replace any damaged, shorted, or corroded wires

  • Perform an oil change and clean dirty actuators or solenoids

  • Repair or replace damaged or defective circuits and related components

  • Repair or replace any damaged or improperly aligned timing components

  • Replace any damaged or defective sensors

  • Replace any damaged or defective camshaft actuator solenoids

  • Replace or repair damaged or defective ECM (rare)

  • Clear all codes, test-drive the vehicle, and rescan to see if any codes reappear

Additional Comments for Consideration Regarding the P2090 Code

Some vehicles need multiple failure cycles to turn on a Check Engine or warning light. If a light is your first notification of a problem, note that it may not be the first occurrence of the issue.

In addition, not all manufacturers place their camshaft sensors in the same location. Some engines with multiple camshafts may have sensors on each one, while others have notches cut into them located near the middle or rear of the shaft. Placement varies so check a service manual for your make and model’s location.

Need Help with a P2090 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

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