Exhaust Pressure Sensor Circuit High

The exhaust pressure sensor measures the pressure in the exhaust system. If it reads higher than 6.5 psi while the engine is running, there might be a blockage or the sensor is faulty.

The engine control module (ECM) is monitoring the exhaust pressure. When the reading exceeds the threshold (typically around 6.5 psi), it triggers the fault code SPN 3352.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 1Check for visible damage to the exhaust pressure sensor wiring and connector. Repair any issues found. Decision: If damaged, repair and retest.
2. 2Test the exhaust pressure sensor signal using a multimeter. Look for a reference voltage between 4.5 to 5.5 volts when the engine is running. Decision: If out of range, replace the sensor.
3. 3Check for exhaust restrictions by using a pressure gauge upstream and downstream of the DPF or catalytic converter. Normal difference should be under 2 psi. Decision: If difference is greater, clean or replace the component causing restriction.

• Blocked exhaust system (like a clogged DPF)
• Faulty exhaust pressure sensor
• Wiring or connector issues to the sensor
• Exhaust leaks before the sensor

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