P0472
UniversalThe Powertrain Control Module (PCM) detects an input voltage from the exhaust pressure sensor that is lower than the specified operating range.
Medium SeverityThe Exhaust Pressure Sensor measures the pressure of exhaust gases and sends this data to the engine's computer. When the computer receives a voltage signal that is too low from this sensor, it triggers code P0472, indicating a potential malfunction that can impact engine performance and emissions.
⚠️ Before You Begin (Safety First)
Always allow the engine to cool before working on exhaust components. Wear appropriate personal protective equipment, including gloves and eye protection. Disconnect the battery before performing any electrical work.
Common Symptoms
- Check Engine Light illumination
- Reduced engine power
- Poor fuel economy
- Excessive exhaust smoke (especially on diesel vehicles)
- Engine entering 'limp mode'
- Failed emissions test
Common Causes
- Faulty exhaust pressure sensor
- Damaged or corroded wiring or connector to the sensor
- Clogged exhaust pressure sensor port or tube
- Faulty Powertrain Control Module (PCM) (rare)
Frequently reported on: 2007-2010 Dodge Ram 2500/3500 (6.7L Cummins), 2008-2010 Ford F-250/F-350 (6.4L Powerstroke), 2007-2010 Chevrolet Silverado 2500/3500 (6.6L Duramax), 2008-2012 GMC Sierra 2500/3500 (6.6L Duramax)
Diagnostic Steps
- Verify the code using an OBD-II scanner.
- Visually inspect the exhaust pressure sensor and its electrical connector and wiring for any signs of damage, corrosion, or loose connections.
- Check the metal or rubber tube connecting the exhaust manifold to the sensor for blockages or cracks.
- If no obvious issues are found, clear the code and test drive the vehicle to see if it returns.
- If the code returns, replace the exhaust pressure sensor. This typically involves disconnecting the electrical connector, removing the pressure tube, and unbolting the sensor.
- After replacement, clear the code and test drive again.
👨🔧 When to Call a Professional
If you've replaced the sensor and checked wiring but the code persists, or if other engine lights illuminate, it's time to consult a professional mechanic for advanced diagnostics, as there might be underlying issues with the exhaust system or PCM.
Commonly Asked Questions
Can I drive with a P0472 code?
While you can often drive, it's not recommended long-term as it can lead to reduced performance, poor fuel economy, and potential damage to the Diesel Particulate Filter (DPF) system in diesel vehicles.
Is replacing the exhaust pressure sensor difficult?
For most vehicles, it's a relatively straightforward DIY task, often requiring basic hand tools. The main challenge can be accessing the sensor itself, which varies by vehicle model.
What else could cause P0472 besides the sensor?
Besides a faulty sensor, common causes include damaged wiring or a corroded connector, or a clogged tube leading from the exhaust manifold to the sensor.
Will P0472 affect my emissions test?
Yes, a P0472 code indicates an emissions system malfunction and will almost certainly cause your vehicle to fail an emissions inspection.
How can I test the exhaust pressure sensor?
You can test the sensor using a multimeter to check for proper voltage output at different engine conditions, or by using a scan tool to monitor live data values from the sensor. Consult your vehicle's service manual for specific voltage ranges.