"B" Camshaft Position - Timing Over-Retarded (Bank 2)
Code P0025 means the PCM has detected that the Bank 2 "B" camshaft (exhaust cam) is over-retarded beyond commanded position. This is the Bank 2 exhaust cam counterpart to P0015. The exhaust cam on Bank 2 cannot advance to the commanded position. Diagnose and repair focused on Bank 2 exhaust cam solenoid, phaser, and timing chain.
What You Might Notice
- Check engine light on
- Rough idle especially when cold
- Sluggish acceleration
- Hard starting
- Stalling at low RPM
- Poor fuel economy
Most Common Causes
- 1
Low or dirty engine oil
Without clean, pressurized oil the Bank 2 exhaust phaser cannot advance, leaving the cam over-retarded.
- 2
Stuck or clogged Bank 2 exhaust VVT solenoid
A blocked or stuck-closed solenoid prevents oil from entering the phaser advance chamber.
- 3
Worn Bank 2 exhaust cam phaser
Oil bleeds from the advance chamber through worn seals, causing the cam to fall back to retarded.
- 4
Stretched Bank 2 timing chain
Chain stretch causes persistent cam timing lag on the Bank 2 exhaust side.
How to Diagnose It
- 1
Check Low or dirty engine oil — Without clean, pressurized oil the Bank 2 exhaust phaser cannot advance, leaving the cam over-retarded.
- 2
Check Stuck or clogged Bank 2 exhaust VVT solenoid — A blocked or stuck-closed solenoid prevents oil from entering the phaser advance chamber.
- 3
Check Worn Bank 2 exhaust cam phaser — Oil bleeds from the advance chamber through worn seals, causing the cam to fall back to retarded.
- 4
Check Stretched Bank 2 timing chain — Chain stretch causes persistent cam timing lag on the Bank 2 exhaust side.
How to Fix It
- 1
Change engine oil and filter
Fresh oil is the first step for any VVT over-retard code.
- 2
Inspect Bank 2 exhaust VVT solenoid
Clean screen, test resistance, replace if needed.
- 3
Monitor Bank 2 exhaust cam timing with scanner
Verify the cam lags commanded position at multiple RPM points.
- 4
Replace Bank 2 exhaust cam phaser
Use OEM-quality replacement if phaser is internally worn.
- 5
Inspect Bank 2 timing chain
Evaluate chain and tensioner if all other checks pass.
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