P047D

Exhaust Pressure Sensor B Circuit High

Q: Is it safe to drive with P047D?

For short trips usually, but the ECM may cut power and, on diesels, block DPF regeneration, so don't put off the repair.

Q: Can I just clear P047D?

The code returns once the high signal is read again unless the sensor, wiring, or blocked tube is fixed.

Exhaust / emissions control Generic OBD-II Medium

What it means

P047D means the ECM has detected an abnormally high signal from exhaust pressure sensor "B", a second sensor monitoring exhaust back-pressure in the EGR or diesel aftertreatment system. The engine still runs, but the false-high reading can trigger reduced power and interfere with soot-filter operation, so it should be diagnosed rather than ignored.

Medium

Can I keep driving? Usually drivable, but the engine may enter reduced-power mode and diesel exhaust-aftertreatment functions can be disrupted, so repair it soon.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Reduced power or limp mode (common on diesels)
Decreased fuel efficiency
Rough running under load

Common causes

Most likely first

Faulty exhaust back-pressure sensor 'B'Likely
Signal wire shorted high or an open in the circuitCommon
Poor or corroded connection at the sensorCommon
Blocked or damaged sensor pressure tube (soot/carbon)Less often
Rarely, a failed ECMLess often

How to diagnose & fix

Work through it in order

Inspect the 'B' exhaust pressure sensor and its pressure tube for soot blockage, cracks, or a loose fitting.
Check the connector and wiring for a short-to-voltage or open on the signal circuit.
Compare the sensor reading to known pressure with a scan tool; replace the sensor if it reads stuck high.
Clear any blockage in the sensor port or tube, then clear the code and re-test.

FAQ

Quick answers

Is it safe to drive with P047D?+

For short trips usually, but the ECM may cut power and, on diesels, block DPF regeneration, so don't put off the repair.

Can I just clear P047D?+

The code returns once the high signal is read again unless the sensor, wiring, or blocked tube is fixed.

Read & clear P047D yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX