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.
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.
Common causes
- high
Open in harness or actuator winding
One of the most commonly reported causes for this code — check this first.
Typical part cost: $220-990
- medium
Connector corroded by exhaust heat or moisture
A plausible cause — test and verify before replacing parts.
Typical part cost: $220-990
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P049F mean?
P049F means "Exhaust Pressure Control Valve B". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P049F?
open in harness or actuator winding; connector corroded by exhaust heat or moisture — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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