P0472 — Exhaust Pressure Sensor A Circuit Low — 6.7 Cummins (EGR + DPF, pre-SCR)

The exhaust back pressure sensor signal voltage is below its valid range on a 6.7L Cummins (EGR + DPF, pre-SCR).

Updated October 15, 2026

What it means

Generic definition: The exhaust back pressure sensor signal voltage is below its valid range. On the 6.7L Cummins this code applies to the exhaust pressure sensor circuit used for back pressure and VGT/exhaust brake control.¹

Most likely causes

1. Exhaust pressure sensor internal short or failed sensor pulling signal low — Sensor output stuck low or shorted internally; typical on this platform. Check sensor, tube and connector.¹
2. Signal wire shorted to ground between sensor and ECM — Wiring harness chafed or pinched causing the signal circuit to read low voltage. Inspect harness routing near exhaust and engine.¹
3. Exhaust pressure sensor tube clogged or blocked, causing false low reading — Restricted pressure tube can cause abnormal sensor behavior; inspect tube for soot blockage or kinks.¹
4. Connector corrosion or poor terminal contact at sensor — Moisture or heat damage at the sensor connector increases resistance or creates a ground path. Clean and inspect terminals.¹

How to diagnose

1. Verify code P0472 is present and check freeze frame for engine conditions.
2. Inspect exhaust pressure sensor, its tube and connector for damage, soot blockage, corrosion, or loose connection.
3. Check sensor signal circuit for short to ground and continuity to ECM; repair wiring as needed.
4. Monitor exhaust pressure sensor voltage with scan tool at idle and during operation; compare to expected range.
5. If wiring and connections are good, replace exhaust pressure sensor and retest.

Parts and tools you may need

• Exhaust pressure sensor
• Exhaust pressure sensor tube
• Multimeter
• Scan tool

Tools you’ll need

• digital multimeter — Checks for short to ground on the exhaust pressure sensor signal wire and verifies reference/ground voltages at the sensor connector.
• OBD-II scan tool — Reads P0472, views freeze frame data, and monitors live exhaust pressure sensor voltage during idle and operation.
• inspection mirror — Allows visual inspection of the exhaust pressure sensor tube and connector for soot blockage, corrosion, or damage in tight under-hood areas.
• hand vacuum pump — Tests sensor response by applying controlled pressure to the sensor port to confirm it changes voltage rather than staying low.

Rough cost and difficulty

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 persist, ECM pin damage is suspected, or VGT/exhaust brake performance is affected, have a qualified diesel technician diagnose and repair the circuit. Do not attempt high-pressure fuel system service.

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