Exhaust Pressure Control Valve "B" Position Sensor/Switch Circuit Intermittent/Erratic
This code means the PCM/ECM has detected an intermittent signal or connection affecting exhaust pressure control valve "b" position sensor/switch circuit. This can keep the emissions system from working correctly, which may raise tailpipe emissions, reduce fuel economy, and prevent readiness monitors from completing.
What You Might Notice
- Check Engine Light illuminated
- Reduced fuel economy
- Failed emissions or readiness monitor
- Rough idle or hesitation
- Possible exhaust smell or smoke
Most Common Causes
- 1
Failed sensor, valve, heater, or emissions actuator
- 2
Loose connector, rubbed-through wiring, or vibration-related fault
- 3
Carbon buildup, restriction, or exhaust leak
- 4
Vacuum leak or pressure hose issue
- 5
PCM/ECM fault or outdated calibration
How to Diagnose It
- 1
Check Failed sensor, valve, heater, or emissions actuator — Inspect for signs of failure and test before replacing.
- 2
Check Loose connector, rubbed-through wiring, or vibration-related fault — Inspect for signs of failure and test before replacing.
- 3
Check Carbon buildup, restriction, or exhaust leak — Inspect for signs of failure and test before replacing.
- 4
Check Vacuum leak or pressure hose issue — Inspect for signs of failure and test before replacing.
- 5
Check PCM/ECM fault or outdated calibration — Inspect for signs of failure and test before replacing.
How to Fix It
- 1
Inspect the sensor, valve, heater, and related hoses or pipes
- 2
Repair wiring or connector damage
- 3
Clean carbon buildup or repair leaks/restrictions
- 4
Replace the failed emissions component if testing confirms it
- 5
Clear the code and run the monitor to verify the fix
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