Broken or disconnected electrical connector at the bank 2 camshaft position actuator solenoid.; Damaged or chafed wiring harness between the DME and the actuator, often due to heat or vibration.; Failed camshaft position actuator solenoid with an open internal coil.; Corroded or loose pins in the actuator connector or DME connector.; Blown fuse or relay supplying power to the actuator circuit (though less common).; Faulty DME driver circuit for the actuator (rare but possible).

DTC codes / BMW codes / P1594

P1594 · BMWB Camshaft Position Actuator Control Open Circuit Bank 2

Q: What does code P1594 mean?

B Camshaft Position Actuator Control Open Circuit Bank 2. The P1594 code on BMW vehicles indicates that the engine control module (DME) has detected an open circuit in the control wiring for the bank 2 camshaft position actuator, which is the solenoid that adjusts camshaft timing. This means the electrical path to the actuator is broken, so the DME cannot command variable valve timing on that bank, potentially affecting engine performance and emissions.

The P1594 code on BMW vehicles indicates that the engine control module (DME) has detected an open circuit in the control wiring for the bank 2 camshaft position actuator, which is the solenoid that adjusts camshaft timing. This means the electrical path to the actuator is broken, so the DME cannot command variable valve timing on that bank, potentially affecting engine performance and emissions.

SystemPowertrain

Code typeBMW specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Rough idle or engine misfire, especially when cold.
Reduced engine power and poor acceleration.
Decreased fuel economy.
Intermittent stalling or hesitation during acceleration.
Unusual engine noises from the valvetrain area.

Common causes, most likely first

Broken or disconnected electrical connector at the bank 2 camshaft position actuator solenoid.
Damaged or chafed wiring harness between the DME and the actuator, often due to heat or vibration.
Failed camshaft position actuator solenoid with an open internal coil.
Corroded or loose pins in the actuator connector or DME connector.
Blown fuse or relay supplying power to the actuator circuit (though less common).
Faulty DME driver circuit for the actuator (rare but possible).

How to diagnose and fix it

Perform a visual inspection of the bank 2 camshaft position actuator connector and wiring for obvious damage or disconnection.
Use a multimeter to check for battery voltage at the actuator connector with the key on, and check for continuity to ground on the control circuit.
Check the resistance of the actuator solenoid coil and compare to specifications; an open circuit indicates a failed solenoid.
Inspect the wiring harness along its route for chafing, heat damage, or corrosion, and repair as needed.
If the solenoid is faulty, replace it with a new unit and clear the fault codes.
If wiring and solenoid are good, check the DME connector for corrosion or loose pins, and repair if necessary.
After repairs, clear codes and perform a road test to verify the fault does not return.

Common Misdiagnosis Traps for P1594

A failed bank 2 camshaft position actuator solenoid is often replaced unnecessarily when the real issue is a damaged connector or wiring harness, so always perform a thorough electrical check first.
The P1594 code can be set by a poor connection at the DME, which is often overlooked because the DME is assumed to be reliable.
On some BMW engines, the bank 2 actuator is located in a hard-to-reach area, and the wiring can be pinched during previous repairs, leading to an open circuit.
This code does not always mean the actuator itself is faulty; it specifically indicates an open circuit, so a shorted or mechanically stuck actuator would set a different code.
Intermittent open circuits can be caused by vibration or temperature changes, so wiggle-testing the harness while monitoring live data can reveal the problem.

Can I keep driving with P1594?

You can drive the vehicle with this code, but avoid aggressive acceleration and high engine loads because the variable valve timing on bank 2 is disabled, which may affect performance and emissions. Have the fault diagnosed soon to prevent potential damage to the catalytic converter from unburned fuel.

Tools that help

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Guidance is general and written for BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.