P0025: B Camshaft Position - Timing Over-Retarded (Bank 2)

What it means

The bank 2 exhaust camshaft remains retarded relative to commanded position. Same root causes as P0012 but on the exhaust cam.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

Variable valve timing uses engine oil and a phaser to position the Bank 2 exhaust camshaft, with movement controlled by an oil control solenoid. The module compares actual cam timing with its target and sets P0025 when the exhaust cam remains more retarded than commanded.

Common causes

Most likely first.

1. Camshaft actuator solenoid sticking or faulty
2. Oil passages restricted or oil level or pressure low
3. Camshaft phaser sticking or worn
4. Wiring or connector fault

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. Capture freeze-frame data and watch commanded versus actual Bank 2 exhaust cam timing to confirm that the cam fails to advance as requested.
2. Check oil level, condition, and viscosity against the vehicle requirements, since insufficient or unsuitable oil can prevent the phaser from responding.
3. Inspect the Bank 2 exhaust cam solenoid connector and harness for loose or corroded terminals, oil intrusion, or physical damage.
4. Test the solenoid and its power, ground, and control circuits against the wiring diagram and manufacturer’s specification.
5. If those checks pass, inspect for restricted oil feed passages or a sticking or worn Bank 2 exhaust cam phaser.

Common fixes

• Correct low oil level or replace unsuitable or contaminated oil and filter with the specified grade.
• Repair damaged wiring or clean and secure the Bank 2 exhaust actuator connector.
• Clean or replace a sticking or electrically faulty Bank 2 exhaust oil control solenoid.
• Clear confirmed oil passage restrictions or replace a faulty Bank 2 exhaust phaser.

Can I keep driving?

If the engine is stable and the warning light is steady, drive only as needed and avoid hard acceleration; retarded exhaust timing can cause poor performance, rough running, or stalling. Stop driving if it stalls repeatedly, runs very roughly, or makes abnormal mechanical noise.