Diesel Oxidation Catalyst Temperature Sensor Circuit Open (Generic)
The P4082 code means the vehicle's onboard diagnostic system has detected: Diesel Oxidation Catalyst Temperature Sensor Circuit Open (Generic). This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $80 - $350 (parts and labor)
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Common Symptoms
- Check Engine Light on
- DOC monitoring disabled
- DPF regen cannot initiate
- Reduced engine power
- Service exhaust warning
Probable Causes (Ranked by Likelihood)
- Open circuit in DOC temperature sensor wiring Very High
- Failed DOC temperature sensor High
- Melted connector near DOC Moderate
- PCM input circuit failure Low
Step-by-Step Diagnostic Procedure
-
Check DOC temperature sensor resistance
-
Inspect wiring for breaks near DOC
-
Verify connector integrity
-
Test PCM input for DOC temp signal
Frequently Asked Questions
What is a DOC?
A diesel oxidation catalyst oxidizes hydrocarbons and carbon monoxide in the exhaust. Its temperature is monitored to ensure proper operation before DPF regeneration.
Can I drive with P4082?
No, DPF regeneration cannot initiate without DOC temperature data. The DPF will clog.
Is the DOC sensor different from the EGT sensor?
They may be the same type of sensor in a different location. The DOC sensor monitors temperature at the diesel oxidation catalyst specifically.
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