Powertrain, generic (extended)

P2BFE Exhaust Flow Control Valve B Position Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

The position feedback of exhaust flap B reads below its lowest valid value. For an analog sensor that means a signal at or near 0 V, typically a short to ground or a missing 5 V supply; for a PWM feedback it means a duty cycle stuck near zero. No manufacturer publishes P2BFE. The nearest documented cases concern valve A: Mazda stores P2BF6 for a low shutter valve position signal and Deutz for a flap voltage below normal. GM watches the second valve of its 23OBDG07 application under its own code, failing below 2 percent duty cycle for 4 seconds. CARB requires such out-of-range checks. Because the two flap sensors often share a supply, a low reading on both sides at once suggests the common reference circuit rather than sensor B; a low on B alone points to its own wiring.

Likely causes

Flap B signal wire shorted to ground
Sensor reference supply open or shorted
Position sensor in actuator B failed

Symptoms

  • Check engine light on
  • Flap B no longer adjusted, exhaust sound unchanged

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

exhaust flow control valve bwiring harnessecm

Related codes

P2BFCP2BFDP2BFFP2BF6P2BF9

References: law.cornell.edu, serdia.deutz.com, gsi.ext.gm.com, static.nhtsa.gov.