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Home >> Honda >> 2014 >> Pilot EX, FWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating/Air Conditioning >> DTC Troubleshooting >> DTC B2980 or DTC indicator 6: A short in the A/C Pressure Sensor Circuit

DTC B2980 or DTC indicator 6: A short in the A/C Pressure Sensor Circuit

  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch to LOCK (0) and then back to ON (II).
  3. Do the self-diagnostic function with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS  ) or the HVAC control unit (see HOW TO USE THE HVAC CONTROL UNIT SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS  ).
  4. Check for DTCs.

    Is DTC B2980 or 6 indicated? 

    YES  -Go to step 5.

    NO  -Intermittent failure.

  5. Check for DTCs.

    Are these DTCs also present; B1234 or 2, and/or B1245 or 7? 

    YES  -Go to step  16.

    NO  -Go to step 6.

  6. Turn the ignition switch to LOCK (0).
  7. Disconnect the A/C pressure sensor 3P connector.
  8. Disconnect HVAC control unit connector A (24P).
  9. Check for continuity between body ground and HVAC control unit connector A (24P) terminal No. 20.
    Fig 1: Checking Continuity Between Body Ground And HVAC Control Unit Connector A (24P) Terminal No. 20
    G08090239Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to body ground in the wire between the HVAC control unit and the A/C pressure sensor.

    NO  -Go to step 10.

  10. Check for continuity between HVAC control unit connector A (24P) terminals No. 14 and No. 20.
    Fig 2: Checking Continuity Between HVAC Control Unit Connector A (24P) Terminals No. 14 And 20
    G08090240Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short in the wire(s).

    NO  -Go to step 11.

  11. Turn the ignition switch to ON (II), and measure the voltage between body ground and HVAC control unit connector A (24P) terminal No. 20.
    Fig 3: Measuring Voltage Between Body Ground And HVAC Control Unit Connector A (24P) Terminal No. 20
    G08090241Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there any voltage? 

    YES  -Repair a short to power in the wire between the HVAC control unit and the A/C pressure sensor. This short may also damage the HVAC control unit. Repair a short to power before replacing the HVAC control unit.

    NO  -Go to step 12.

  12. Turn the ignition switch to LOCK (0).
  13. Reconnect HVAC control unit connector A (24P).
  14. Turn the ignition switch to ON (II).
  15. Measure the voltage between HVAC control unit connector A (24P) terminals No. 4 and No. 14, and between HVAC control unit connector A (24P) terminals No. 4 and No. 20.
    Fig 4: Measuring Voltage Between HVAC Control Unit Connector A (24P) Terminals No. 4 And 14 And Between Terminals No. 4 And 20
    G08090242Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5 V? 

    YES  -Replace the A/C pressure sensor.

    NO  -Check for loose wires or poor connections at HVAC control unit connector A (24P) and at the A/C pressure sensor 3P connector. If the connections are good, substitute a known-good HVAC control unit, and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION  ).

  16. Turn the ignition switch to LOCK (0), and disconnect HVAC control unit connector A (24P).
  17. Disconnect these items:
    • Front air mix control motor
    • Rear air mix control motor
    • A/C pressure sensor
  18. Check for continuity between HVAC control unit connector A (24P) terminal No. 14 and body ground.
    Fig 5: Checking Continuity Between HVAC Control Unit Connector A (24P) Terminal No. 14 And Body Ground
    G08090243Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to body ground in the wire.

    NO  -Go to step 19.

  19. Turn the ignition switch to ON (II), and check the same terminal for voltage to body ground.
    Fig 6: Checking HVAC Control Unit Connector A (24P) Terminal For Voltage To Body Ground
    G08090244Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there any voltage? 

    YES  -Repair a short to power in the wire. This short may have also damaged the HVAC control unit. Repair a short to power before replacing the HVAC control unit.

    NO  -Go to step 20.

  20. Turn the ignition switch to LOCK (0).
  21. Reconnect HVAC control unit connector A (24P).
  22. Turn the ignition switch to ON (II), and measure the voltage between HVAC control unit connector A (24P) terminal No. 14 and body ground.
    Fig 7: Measuring Voltage Between HVAC Control Unit Connector A (24P) Terminal No. 14 And Body Ground
    G08090245Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 5 V? 

    YES  -Go to step 23.

    NO  -Check for a loose wire or poor connection at HVAC control unit connector A (24P). If the connection is good, substitute a known-good HVAC control unit and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION  ).

  23. While checking the same terminal for voltage to ground, reconnect these items individually and note the voltage reading each time:
    • Front air mix control motor
    • Rear air mix control motor
    • A/C pressure sensor
      Fig 8: Checking HVAC Control Unit Connector A (24P) Terminal For Voltage To Ground
      G08090246Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Does the voltage remain at about 5 V? 

    YES  -Substitute a known-good HVAC control unit and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION  ).

    NO  -Replace the component that caused the voltage drop.

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