P2B7EEVAP System Pressure Sensor/Switch C Circuit Intermittent
- 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
- P2B7E covers a signal from EVAP pressure sensor C that drops out or jumps for brief moments instead of failing for good. No manufacturer documents P2B7E publicly; Audi and VW use only P2B7A and P2B7B, VW also P2B7C and P2B7D, for this sensor. How such a check can work is shown by Mitsubishi's 2023 Outlander PHEV for its tank pressure sensor (P24D9): during the parked leak test it counts how often the signal crosses its own filtered value and sets the code after more than 20 crossings. Loose terminals, a chafed harness near the tank, moisture in the connector or electrical interference – the cause Mercedes-AMG found behind P2B7B – are typical. CARB 13 CCR 1968.2 (e)(15) asks for circuit checks on EVAP inputs. Moving the harness gently while the reading is displayed helps locate the spot.
- What you may notice
- Check engine light comes and goes
- Pressure reading jumps in live data
- Fault often appears only on rough roads or in wet weather
- Likely causes
- LikelyLoose or corroded terminal at the sensor connector
- PossibleHarness chafing near the tank or along the underbody
- PossibleElectrical interference on the signal line
- RarePressure sensor C with an intermittent internal fault
- 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: €40 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.