Emission Control System Pressure Sensor Fault
The emissions pressure sensor signal is out of expected range.
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What it means (plain English)
Your truck's emissions pressure sensor is sending a signal that's either too high or too low, meaning it’s not working right and can affect exhaust treatment.
What the computer is actually seeing
The ECM expects the emissions pressure sensor to output a signal voltage between 0.5V (low pressure) and 4.5V (high pressure). If the value is less than 0.4V or greater than 4.6V for a sustained period, it triggers this fault code.
What a healthy reading looks like
Expected signal voltage from the emissions pressure sensor is between 0.5V and 4.5V under normal operating conditions; pressure readings should align with engine load and RPM.
Guided diagnostic — the DiagCoach way
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.
- 11. Inspect the wiring and connectors leading to the emissions pressure sensor for damage or corrosion.
- 22. Check for any exhaust leaks around the emissions system components. Repair if necessary.
- 33. Using a scan tool, monitor the voltage of the emissions pressure sensor. Is it between 0.5V and 4.5V?
- 44. If the signal is out of range, test the emissions pressure sensor by disconnecting it and checking resistance (should be near specific manufacturer specs).
- 55. If the sensor tests faulty, replace it. If it tests okay, the issue may be within the wiring or the ECM.
Common causes
- Faulty emissions pressure sensor
- Wiring issues or short circuits in the sensor circuit
- Clogged or damaged exhaust system
- ECM fault
- Incorrectly installed or damaged sensor connector
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; drivable but it's best to fix soon to prevent emissions issues.
Will this code come back after I clear it?
If the issue isn’t resolved, yes, it will return.
Why does this code pair with others?
It often relates to overall emission control faults in the system, affecting multiple sensors and components.
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