P2CB7Turbocharger/Supercharger Boost Pressure B Not Detected - Mechanical
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2CB7 states that charger B delivers practically no boost although the operating point calls for it, and that the reason is likely mechanical rather than electrical: the pressure measured after the second compressor hardly rises above ambient. It mirrors P2262 for charger A and is relevant only to engines with two separately monitored boost paths. No manufacturer documents P2CB7 publicly. For the A version, Volvo technical journal 31319 traced P2262 on a 2016 four-cylinder engine to a fresh-air hose that had slipped off the air filter housing. CARB requires boosted engines to detect underboost. While P02CB measures a shortfall against target, P2CB7 stands for boost missing altogether; acceleration is flat and torque is often limited.
- What you may notice
- Clearly flat acceleration
- MIL on, power limited
- Unusual hissing or no turbo sound
- Likely causes
- LikelyIntake or charge air hose of charger B detached or split
- PossibleWastegate or bypass of charger B stuck open
- PossibleDamaged or seized turbocharger B
- RareActuator linkage or vacuum supply to charger B failed
- 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: €30 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.