P0017 — Crankshaft Position - Camshaft Position Correlation, Bank 1 Sensor B

What it means

The same correlation check as P0016 but for bank 1 sensor B, which on most engines is the exhaust camshaft. The measured phase between crankshaft and exhaust cam is outside tolerance, so valve overlap and internal exhaust gas recirculation are wrong, giving rough idle, poor throttle response and higher emissions. On BMW this points to the exhaust side VANOS unit, its solenoid, or a chain that has jumped a tooth on the exhaust sprocket, often together with the well known N47 and N20 chain wear.

Likely causes (most common first)

1. Exhaust side variable valve timing solenoid clogged with sludge or electrically failed
2. Worn timing chain and guides letting the exhaust cam drift out of phase
3. Worn or leaking exhaust camshaft phaser unable to hold the angle
4. Low oil pressure or degraded oil starving the phaser
5. Faulty bank 1 exhaust camshaft position sensor or damaged cam trigger wheel
6. Chain fitted one tooth out or a loose exhaust cam sprocket bolt after previous work

Can you drive with it?

Short careful trips are acceptable, but any chain noise or power loss means stop driving and check the timing at once.