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P code powertrain Medium severity

P1437 A/C Evaporator Air Temperature Circuit High

The OBD2 code P1437 indicates that the A/C evaporator air temperature sensor circuit is reading a high voltage, which may suggest a malfunction in the sensor or its wiring

Definition

The OBD2 code P1437 indicates that the A/C evaporator air temperature sensor circuit is reading a high voltage, which may suggest a malfunction in the sensor or its wiring

Common causes

  • Faulty A/C evaporator temperature sensor
  • Wiring issues (shorts or open circuits)
  • Poor electrical connections
  • Faulty A/C control module
  • Corroded connectors
  • Malfunctioning HVAC control unit
  • Incorrect refrigerant levels

Common misdiagnoses

  • Faulty A/C evaporator temperature sensor
  • Wiring issues or shorts in the circuit
  • Faulty A/C control module
  • Refrigerant level issues
  • Faulty A/C compressor
  • HVAC control panel malfunction
  • Incorrectly diagnosed cabin temperature issues
  • Faulty engine coolant temperature sensor

Troubleshooting steps

  1. 1. Check the A/C System

  2. 2. Ensure that the A/C system is properly charged with refrigerant. Low refrigerant levels can cause various issues, including incorrect temperature readings

  3. 3. Inspect the Wiring and Connectors

  4. 4. Examine the wiring and connectors associated with the A/C evaporator temperature sensor. Look for signs of damage, corrosion, or loose connections that could affect the signal

  5. 5. Test the A/C Evaporator Temperature Sensor

  6. 6. Use a multimeter to test the resistance of the evaporator temperature sensor. Compare the readings to the specifications provided in the vehicle's service manual. If the sensor is out of range, it may need to be replaced

  7. 7. Check for Short Circuits

  8. 8. Inspect the wiring harness for any short circuits or grounding issues that could cause the high signal reading. This may involve checking for continuity and ensuring that the wires are not touching any metal surfaces

  9. 9. Scan for Additional Codes

  10. 10. Use an OBD-II scanner to check for any other related trouble codes that may provide additional context for the issue. Addressing any other codes may help resolve the P1437 code

  11. 11. Inspect the A/C Control Module

  12. 12. If the sensor and wiring are in good condition, the issue may lie within the A/C control module. Check for any software updates or known issues with the module

  13. 13. Clear the Code and Test Drive

  14. 14. After performing the necessary repairs or replacements, clear the trouble code using an OBD-II scanner. Take the vehicle for a test drive to see if the code returns

  15. 15. Consult the Service Manual

  16. 16. Refer to the vehicle's service manual for specific diagnostic procedures and specifications related to the A/C evaporator temperature circuit

  17. 17. Seek Professional Help

  18. 18. If the issue persists after performing the above steps, it may be best to consult a professional mechanic or technician who has experience with A/C systems and OBD-II diagnostics. By following these steps, you should be able to identify and resolve the issue related to the P1437 code