P25E6: B Camshaft Position - Stuck In Locked Position Bank 2

What it means

Camshaft phaser B on bank 2 will not unlock from its base position. The phaser stays at the park-lock angle and cannot be advanced or retarded as commanded.

At a glance

• Usually lights the check-engine light

How it works

Camshaft phaser B on bank 2 varies that bank's cam timing by directing engine oil through its control valve. The control module compares commanded and reported cam position and sets this code when the phaser remains at its park-lock angle instead of moving as commanded.

Common causes

Most likely first.

1. Park-lock pin stuck in the locked groove
2. Low oil pressure cannot push the lock pin out
3. Oil control valve blocked by debris

Symptoms

• Check engine light on
• Power loss especially in mid-rpm range
• Possible rough idle or stalling
• Increased fuel consumption

How to diagnose it

1. Review freeze-frame data and live commanded versus actual cam angle for phaser B on bank 2 to confirm it stays at its parked position.
2. Check engine oil level, condition, and specified viscosity because low or unsuitable oil can prevent the park-lock pin from releasing.
3. Inspect the bank 2 phaser B oil control valve connector and wiring for damage, poor contact, or contamination.
4. Check the oil control valve and its passages for debris or sticking that could restrict oil flow to the bank 2 phaser B.
5. Measure engine oil pressure and test the valve and phaser operation using the manufacturer's procedures to distinguish low pressure or a valve fault from a stuck lock pin.

Common fixes

• Correct the oil level and replace degraded or incorrect-viscosity oil and filter.
• Clean or replace a debris-blocked bank 2 phaser B oil control valve as appropriate.
• Repair damaged wiring or connector terminals for the bank 2 phaser B valve.
• Repair an oil-pressure problem that prevents the park-lock pin from releasing.
• Replace or repair the bank 2 phaser B if its lock pin is mechanically stuck.

Can I keep driving?

If the engine runs smoothly, a short, gentle trip may be possible, but avoid hard acceleration because bank 2 cam timing may remain fixed and reduce power. Stop driving if it stalls, runs very roughly, or develops unusual engine noise; continued operation can worsen drivability and timing-related damage.