P0471 — Exhaust Pressure Sensor A Circuit Range/Performance — 6.7 Cummins (SCR / DEF)
Exhaust Pressure Sensor A Circuit Range/Performance
What it means
The powertrain control module has detected that the exhaust pressure sensor A signal is outside the expected range or is performing inconsistently. On the 6.7L Cummins SCR/DEF platform this is the exhaust pressure sensor used for DPF differential pressure monitoring and regeneration control.1
Most likely causes
- Exhaust pressure sensor A internal failure or drift — Sensor output is out of range or slow to respond; typical range/performance fault.1
- Wiring/connector fault to exhaust pressure sensor A — Chafed, corroded or loose harness/connector causing intermittent or biased signal.1
- Exhaust pressure sensor A supply/ground voltage issue — Reference voltage or ground drop causing out-of-range reading.1
- Exhaust pressure sensing lines/tubing restriction or leak — Clogged or leaking pressure signal tubing to the sensor gives false pressure reading.1
- DPF/exhaust restriction causing actual pressure out of expected range — High backpressure from a plugged DPF or exhaust blockage can drive sensor reading beyond calibrated range.1
- PCM calibration or software anomaly — Incorrect sensor scaling or software glitch causing range/performance detection.1
How to diagnose
- Verify freeze-frame and repeatability of P0471; check for accompanying DPF/regeneration or exhaust codes.
- Inspect exhaust pressure sensor A connector and wiring for corrosion, chafing, moisture; repair as needed.
- Check sensor supply voltage and ground per service information; confirm stable reference.
- Remove and inspect pressure signal tubing for blockage, cracks, or moisture; blow through or replace.
- Command sensor reading with scan tool and compare to a known-good sensor or substitute; evaluate response to pressure changes.
- Inspect DPF and exhaust for restriction; review differential pressure data during idle and loaded conditions.
- If electrical and mechanical checks pass, reprogram/verify PCM calibration per latest TSBs.
Common mistake to avoid
Cleaning or replacing the DPF before checking its pressure sensor and tubes. Cracked, melted, plugged or wet sensor tubes, or a failing sensor, can set DPF codes while the filter itself is fine. They are cheap to check; clear and verify them before touching the filter. Source: FleetRabbit — P2002 DPF efficiency code causes and fixes.
Parts and tools you may need
- Scan tool with live data and bi-directional control
- Digital multimeter
- Back-probe pins / breakout box
- Compressed air / low-pressure regulated air source
- Replacement exhaust pressure sensor A
- Replacement pressure signal tubing and fittings
Tools you’ll need
- OBD-II scan tool — Reads P0471 freeze-frame and live exhaust pressure sensor A data to verify repeatability and compare commanded vs actual pressure during idle and load.
- digital multimeter — Checks sensor supply voltage, ground integrity, and signal voltage range to rule out wiring or reference issues causing out-of-range readings.
- hand vacuum/pressure pump with gauge — Applies controlled pressure to the sensor signal line to test sensor response and detect tubing blockage or leaks affecting P0471.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| ECM/PCM software update | — | 0.5–1.5 hrs | Shop |
| Wiring or connector repair | $10–$100 | 1–4 hrs | DIY with tools and a manual |
| Exhaust backpressure sensor | $60–$200 | 0.5–1.5 hrs | Easy DIY |
| DPF professional cleaning (bake and blow) | $300–$700 | 1–3 hrs | Shop |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If wiring faults are found in the engine bay or exhaust area, or if DPF restriction is suspected, have a qualified diesel technician perform inspection and testing. Do not disassemble high-temperature exhaust components without proper training and equipment.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
Repair videos: P0471 on the 6.7 Cummins '13+
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
Run a 6.7 Cummins (SCR / DEF)? This goes straight to the editor — it is not published.