P4083 moderate

Diesel Oxidation Catalyst Temperature Sensor Circuit Low (Generic)

The P4083 code means the vehicle's onboard diagnostic system has detected: Diesel Oxidation Catalyst Temperature Sensor Circuit Low (Generic). This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$80 - $350 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • DOC temperature reading too low
  • DPF regen may not initiate properly
  • Increased idle emissions

Probable Causes (Ranked by Likelihood)

  • Short to ground in DOC sensor wiring Very High
  • DOC sensor reading low High
  • Corroded connector at DOC Moderate
  • Ground fault in sensor circuit Low

Step-by-Step Diagnostic Procedure

  1. Test DOC sensor resistance at known temperature

  2. Check for shorts to ground

  3. Inspect connector for corrosion

  4. Compare DOC sensor reading to expected value

Frequently Asked Questions

Can a low DOC temp prevent DPF regen?

Yes, the PCM needs to verify the DOC has reached light-off temperature before initiating DPF regeneration.

Can I drive with P4083?

You can drive short distances. DPF regeneration timing may be affected.

What is DOC light-off temperature?

The temperature at which the DOC begins catalyzing exhaust gases, typically around 350-450 degrees F.

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