The P0472 trouble code indicates that your vehicle’s Exhaust Pressure Sensor “A” is reporting a voltage reading that’s too low for the expected range. This sensor is crucial for managing diesel emissions compliance, turbocharger efficiency, and DPF (Diesel Particulate Filter) regeneration cycles.
This guide explains what causes the P0472 code, what symptoms to watch for, and how to diagnose and fix it using iCarsoft CR MAX or CR ULTRA P.
What Does Code P0472 Mean?
P0472 stands for “Exhaust Pressure Sensor A Circuit Low.” It means the Engine Control Module (ECM) detected a voltage signal lower than the manufacturer’s threshold—usually less than 0.25V. This sensor helps determine exhaust backpressure, which directly influences EGR operation and DPF cleaning frequency.
Symptoms of P0472
- Check Engine Light (CEL) illuminated
- Reduced turbocharger boost
- Frequent DPF clogging or regen failure
- Sluggish acceleration or limp mode
- Higher fuel consumption
- Increased exhaust smoke
Causes of P0472
- Faulty or contaminated exhaust pressure sensor
- Blocked or melted pressure tube
- Damaged wiring harness or connector corrosion
- Short to ground or low reference voltage in sensor circuit
- Faulty ECM (rare)
How to Diagnose P0472 (Step-by-Step)
- Connect the iCarsoft CR ULTRA P and perform a full system scan.
- Confirm that P0472 is stored and note any related codes such as P0471 or P0473.
- Visually inspect the exhaust pressure sensor and tubing for soot buildup or melting.
- Use live data on the CR ULTRA P to check the voltage from the exhaust pressure sensor at idle and under load.
- If voltage remains constant or below range, test continuity on the signal and ground wires.
- Replace the sensor if wiring tests good and signal voltage remains too low.
How to Fix Code P0472
- Clean or replace the exhaust pressure sensor and pressure tubing.
- Inspect and repair damaged wiring or connectors.
- Clear stored codes using the iCarsoft tool and recheck after a short drive.
- Perform a DPF regeneration if necessary (available in CR MAX / CR ULTRA P).
Real Case Example
A 2018 Mercedes Sprinter 2.1L diesel presented with the P0472 code and low turbo power. Using the iCarsoft CR ULTRA P, the technician confirmed voltage stuck at 0.08V. The exhaust pressure hose was found clogged with soot. After cleaning the hose and replacing the sensor, voltage normalized to 1.2V, and the code cleared successfully.
FAQs About P0472
1. Can I drive with the P0472 code?
You can drive short distances, but prolonged driving with this code can lead to DPF clogging, reduced performance, and higher exhaust emissions. Fix it as soon as possible.
2. Where is the Exhaust Pressure Sensor located?
Typically near the exhaust manifold or turbocharger, with a small metal or rubber hose connecting it to the exhaust system. You can refer to OBD-Codes.com’s guide for sensor location visuals by model.
3. What voltage should the exhaust pressure sensor read?
Normal readings are between 0.5V and 4.5V. Readings below 0.25V trigger code P0472, while above 4.5V typically cause code P0473.
4. Is the P0472 code related to the EGR or DPF system?
Yes. Incorrect exhaust pressure data can disrupt both EGR valve operation and DPF regeneration cycles. For more on DPF systems, check the EU Emissions Standards Overview.
5. Can cleaning the sensor fix the issue?
Yes—if the fault is caused by soot buildup. Remove the sensor carefully, clean it with electrical contact cleaner, and blow compressed air through the tube. Do not use brake cleaner or harsh solvents.
6. How can the iCarsoft CR MAX help?
The iCarsoft CR MAX allows you to:
- View real-time exhaust pressure data
- Command DPF regeneration
- Reset adaptive values
- Graph live voltage to confirm repairs
7. What happens if I ignore P0472?
Ignoring it may cause increased soot buildup, turbo inefficiency, and even DPF failure. Over time, it can lead to costly repairs and EPA non-compliance.
8. Do I need OEM parts?
Always use OEM-quality exhaust pressure sensors. Aftermarket parts often have poor calibration, leading to recurring codes and inaccurate pressure readings.
9. How do I confirm that the issue is fixed?
After cleaning or replacing the sensor, clear all codes with your iCarsoft tool and perform a road test. Monitor the live pressure readings and confirm the Check Engine Light remains off after multiple drive cycles.
Recommended Tools for Fixing P0472
- iCarsoft CR MAX – Advanced diagnostics, graphing, and DPF/EGR functions.
- iCarsoft CR ULTRA P – Bluetooth-enabled, supports live data, special functions, and injector coding.
