P05CFCold Start B Camshaft Position Timing Performance Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- During catalyst heating after a cold start the engine module commands a specific cam phaser position for more residual gas and exhaust heat; CARB requires this to be monitored under codes separate from the normal cam codes. These 'performance' codes are GM's current form (since about 2015/16; older GM engines and Ford use the direction codes P052A ff and P054A ff): fault when commanded and actual position differ by more than 4° or 6° once the target is stable. P05CF watches exhaust camshaft B on bank 2 of a V engine – the cold-start counterpart of P0024. GM's 3.6 L V6 sets it above 4° in 40 of 100 samples, type B, two trips. Its predecessor in GM's 2011 V6 (Saab 9-4X) was P054D, above 6° for 1 s.
- What you may notice
- Check engine light on (GM mostly after two trips)
- Often no noticeable symptoms, possibly rough cold idle
- Higher cold-start emissions
- Likely causes
- LikelyInsufficient cold oil supply: wrong viscosity, low level, worn oil
- PossibleOil control valve bank 2 sticking or screen clogged
- PossiblePhaser worn or lock pin not releasing; on electric phasers a damaged phaser motor
- RareTiming chain stretched or skipped
- RareEngine module software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.