P1525

What the Code Means

Code P1525 points to an open circuit in the VANOS intake solenoid. VANOS (Variable Nockenwellen Steuerung) varies the timing of the intake and exhaust valves based on engine operating conditions. That gives optimal cylinder filling, lower fuel consumption, and reduced exhaust emissions.

The VANOS intake solenoid is driven by a signal from the engine control module (DME) and meters oil flow to the phasing mechanism. With the solenoid circuit open, the DME can't control intake camshaft position, so the timing locks into a fail-safe mode and the engine loses efficiency.

The code falls into the moderate severity category: the car can still be driven, but with limits on power and fuel economy.

Symptoms

• Loss of power, especially at low rpm
• Hesitation and flat spots under acceleration
• Rough idle
• Increased fuel consumption
• Hard cold starts, long cranking
• SES (Service Engine Soon) light comes on

Diagnosis and Repair

The source data has no step-by-step diagnostic and repair procedure for code P1525. Check the VANOS intake solenoid circuit: wiring integrity, the connector, and winding resistance. If the open circuit is confirmed, replace the solenoid or, if needed, carry out a more extensive VANOS repair.

The source lists the possible jobs: VANOS replacement (including a DIY job) and replacing the solenoid on its own. It also notes that the exhaust camshaft hub may need to be replaced as well.