Exhaust Pressure Sensor Circuit Intermittent (Generic)
The P4039 code means the vehicle's onboard diagnostic system has detected: Exhaust Pressure Sensor Circuit Intermittent (Generic). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light intermittent
- Sporadic DPF regeneration timing issues
- Inconsistent exhaust pressure data
- Occasional reduced power
Probable Causes (Ranked by Likelihood)
- Loose exhaust pressure sensor connector Very High
- Moisture in pressure sense tube High
- Intermittent wiring fault Moderate
- Pressure tube connection loose Low
Step-by-Step Diagnostic Procedure
-
Wiggle test connector while monitoring live data
-
Check pressure tubes for moisture accumulation
-
Inspect wiring for intermittent breaks
-
Verify tube connections at sensor and exhaust
Frequently Asked Questions
Can moisture cause intermittent readings?
Yes, water in the pressure sense tubes is a very common cause of intermittent readings.
How do I remove moisture from the tubes?
Disconnect the tubes and blow them out with compressed air.
Can I drive with P4039?
You can drive short distances. Schedule a repair to prevent DPF loading issues.
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