What it means
Exhaust pressure sensor B signal jumps or drops out intermittently. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Exhaust pressure sensor B measures exhaust pressure for DPF monitoring or turbo control, depending on the vehicle. The control module sets P047E when sensor B’s signal jumps or drops out intermittently instead of changing consistently with exhaust conditions.
Common causes
Most likely first.
- Intermittent connector
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check-engine light on
- Intermittent loss of power or sluggish acceleration
- Exhaust smoke may vary
- Fuel economy may fluctuate
How to diagnose it
- Record freeze-frame data and watch sensor B live data to identify when the signal becomes erratic.
- Inspect sensor B’s connector for loose fit, corrosion, water ingress, or terminals that may move in the connector.
- Trace the sensor B harness for chafing or contact with a vibrating or hot component.
- With live data monitored, gently move the sensor B connector and harness to see whether the signal jumps or drops out.
- Test the sensor, wiring continuity, and pressure passage under the manufacturer’s procedure to distinguish an electrical dropout from a pressure problem.
Common fixes
- Reseat and secure sensor B’s connector.
- Clean or repair connector terminals with intermittent contact.
- Repair chafed wiring and secure the harness away from vibration or heat.
- Replace sensor B if it intermittently fails testing with sound wiring and a clear pressure passage.
Can I keep driving?
Drive cautiously and avoid high loads if power or acceleration is fluctuating. Stop if the engine loses substantial power; intermittent readings can disrupt DPF or turbo control and vary exhaust smoke.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.