What it means
Camshaft phaser B on bank 2 follows the commanded angle too slowly, oscillates, or shows steady-state error outside tolerance. Closed-loop control of cam timing is degraded.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The B camshaft phaser on bank 2 adjusts valve timing in response to oil-control commands. The module compares commanded cam angle with the measured angle; this code sets when the B cam on bank 2 responds too slowly, oscillates, or remains outside its expected position.
Common causes
Most likely first.
- Oil control valve spool sticks under varnish
- Stretched timing chain shifts cam reference
- Wrong oil viscosity slows phaser response
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
How to diagnose it
- Review freeze-frame data and graph commanded versus actual B cam angle on bank 2 to see whether the error is slow response, oscillation, or steady offset.
- Check oil level, condition, and viscosity against the manufacturer's specification because unsuitable or degraded oil can slow phaser response.
- Inspect the bank 2 B-phaser oil control valve connector and wiring for damage, loose pins, or corrosion.
- Use scan-tool commands, where supported, to observe whether the bank 2 B cam follows changes in commanded angle smoothly.
- Test the B-phaser oil control valve for varnish-related sticking and verify the timing-chain reference if valve operation and oil supply are satisfactory.
Common fixes
- Replace oil and filter with the specified grade if the oil is degraded or incorrect.
- Clean or replace a varnish-sticking bank 2 B-phaser oil control valve.
- Repair damaged or loose wiring or connector terminals at the bank 2 B-phaser valve.
- Replace a stretched timing chain and correct its timing if the cam reference is shifted.
Can I keep driving?
If the engine runs smoothly, limit heavy acceleration and have the fault addressed soon because degraded bank 2 B cam control can reduce power and increase fuel use. Stop driving if it stalls or runs severely rough.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.