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P202APowertrainFix Soon

Reductant Tank Heater Control Circuit/Open

This code means the PCM/ECM has detected an open in the control circuit affecting reductant tank heater. This can keep the emissions system from working correctly, which may raise tailpipe emissions, reduce fuel economy, and prevent readiness monitors from completing.

Schedule a repair soon — this issue will worsen and may cause additional damage if ignored.

What You Might Notice

  • Check Engine Light illuminated
  • Failed emissions or readiness monitor
  • Reduced fuel economy
  • Cold-start drivability issue
  • No obvious symptom besides the warning light

Most Common Causes

  1. 1

    Open circuit in the affected wiring or component

  2. 2

    Wiring damage or poor electrical connection

  3. 3

    Carbon buildup, restriction, or exhaust leak

  4. 4

    Vacuum leak or pressure hose issue

  5. 5

    PCM/ECM fault or outdated calibration

How to Diagnose It

  1. 1

    Check Open circuit in the affected wiring or componentInspect for signs of failure and test before replacing.

  2. 2

    Check Wiring damage or poor electrical connectionInspect for signs of failure and test before replacing.

  3. 3

    Check Carbon buildup, restriction, or exhaust leakInspect for signs of failure and test before replacing.

  4. 4

    Check Vacuum leak or pressure hose issueInspect for signs of failure and test before replacing.

  5. 5

    Check PCM/ECM fault or outdated calibrationInspect for signs of failure and test before replacing.

How to Fix It

  1. 1

    Inspect the sensor, valve, heater, and related hoses or pipes

  2. 2

    Repair wiring or connector damage

  3. 3

    Clean carbon buildup or repair leaks/restrictions

  4. 4

    Replace the failed emissions component if testing confirms it

  5. 5

    Clear the code and run the monitor to verify the fix

Need a deeper diagnosis?

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