What does it mean?
P1527 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Variable Camshaft Timing (VANOS) Circuit Malfunction .
Symptoms
- Check engine light on with an uneven idle
- Clear loss of torque, mostly in the low and mid range
- Rattling noise on start-up or during acceleration
- Higher fuel consumption than usual
- Hesitation when pulling away and a lazy response to throttle
- Engine may run in a protective mode with limited performance
Likely causes
- Failed variable timing solenoid, electrically or because its filter screen is clogged
- Sludge and varnish in the oil restricting the phaser feed
- Low oil level or oil pressure below what the phaser needs
- Damaged wiring or a corroded connector at the solenoid
- Worn phaser unit or a broken locking pin, so the camshaft cannot hold its commanded position
- Timing chain stretch or a weak tensioner shifting the cam angle
- Camshaft or crankshaft position sensor signal errors upsetting the correlation calculation
How to fix it
- Check the oil level and condition, and change the oil and filter if the service is overdue
- Remove the timing solenoid, inspect the plunger for free movement and clean or replace the filter screen
- Measure the solenoid resistance and check its supply, ground and control circuits
- Command the solenoid with a scan tool and watch actual against target camshaft angle in live data
- Inspect the connector and harness for oil contamination, corrosion and chafing
- Verify camshaft to crankshaft correlation and inspect the chain and tensioner if the deviation stays
- Replace the solenoid first, then the phaser unit only if the hydraulic and electrical sides are proven good