OBD-II code · Powertrain (generic)
P049F Exhaust Pressure Control Valve B
A general circuit fault is detected on the second exhaust pressure control valve (B) - used for example on dual exhaust brakes, twin-bank diesels with separate back-pressure flaps, or for DPF regeneration backpressure assist on the second bank. The ECU loses control of this stage.
Is it safe to drive with P049F?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in harness or actuator winding
- PossibleConnector corroded by exhaust heat or moisture
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3.5 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Pressure Valve B, Exhaust Pressure Actuator B
Related codes
- P0475Exhaust Pressure Control Valve A
- P049CEGR B Flow Excessive Detected
- P049DEGR A Control Position Exceeded Learning Limit
- P049EEGR B Control Position Exceeded Learning Limit
- P04A0Exhaust Pressure Control Valve B Range or Performance
- P04A1Exhaust Pressure Control Valve B Low
- P04A2Exhaust Pressure Control Valve B High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.