Broken or disconnected wire in the camshaft actuator circuit (open circuit).; Corroded or damaged electrical connector at the camshaft actuator solenoid.; Failed camshaft position actuator solenoid (open coil).; Faulty engine control module (DME) driver for the actuator circuit, though rare.; Rodent damage to the wiring harness.; Oil contamination or sludge affecting the actuator solenoid electrical connection.

DTC codes / BMW codes / P1525

P1525 · BMWA Camshaft Position Actuator Control Open Circuit Bank 1

Q: What does code P1525 mean?

A Camshaft Position Actuator Control Open Circuit Bank 1. P1525 on BMW vehicles indicates that the engine control module (DME) has detected an open circuit in the wiring for the bank 1 camshaft position actuator, which is the solenoid that adjusts camshaft timing. The computer expects a certain electrical load when commanding the actuator, and an open circuit means no current can flow, so the variable valve timing system cannot function on that bank.

P1525 on BMW vehicles indicates that the engine control module (DME) has detected an open circuit in the wiring for the bank 1 camshaft position actuator, which is the solenoid that adjusts camshaft timing. The computer expects a certain electrical load when commanding the actuator, and an open circuit means no current can flow, so the variable valve timing system cannot function on that bank.

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 uneven engine operation, especially when cold.
Reduced engine performance and poor fuel economy due to disabled variable valve timing.
In some cases, the engine may enter limp mode or have difficulty starting.
A noticeable lack of power at higher engine speeds.

Common causes, most likely first

Broken or disconnected wire in the camshaft actuator circuit (open circuit).
Corroded or damaged electrical connector at the camshaft actuator solenoid.
Failed camshaft position actuator solenoid (open coil).
Faulty engine control module (DME) driver for the actuator circuit, though rare.
Rodent damage to the wiring harness.
Oil contamination or sludge affecting the actuator solenoid electrical connection.

How to diagnose and fix it

Perform a visual inspection of the actuator solenoid connector and wiring for damage or corrosion.
Use a multimeter to check the resistance of the camshaft actuator solenoid; compare to specification.
Check for battery voltage at the actuator connector with the key on and engine off, and verify the ground circuit.
Inspect the wiring harness between the DME and the actuator for continuity and shorts to ground or power.
If the solenoid fails resistance or functional tests, replace the camshaft position actuator solenoid.
Clear the fault codes and perform a road test to verify the repair; if the code returns, further diagnose the DME and circuit.

Common Misdiagnosis of P1525

A failed camshaft actuator solenoid often tests fine when cold but fails when hot, so resistance checks should be done both cold and after warming the engine.
The open circuit may be intermittent, caused by a chafed wire that only loses contact over bumps or when the engine moves under load.
Oil sludge or debris can block the actuator solenoid screen, causing mechanical binding that mimics an electrical open circuit; always check oil condition and screen.
The DME driver for the actuator can fail, but this is rare; do not replace the DME without confirming all wiring and solenoid tests first.
This code can be set by a poor connection at the DME connector itself, so inspect and clean DME pins if all other tests pass.

Can I keep driving with P1525?

You can generally drive the vehicle with this code, but avoid aggressive acceleration and high engine speeds because the variable valve timing is disabled, which may reduce performance and fuel economy. Have the fault diagnosed soon to prevent potential secondary issues.

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.