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Home >> Nissan-Datsun >> 2004 >> Altima S, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 1075 (Heater & Air Conditioning Control System (Automatic Air Conditioner)) >> DTC/Circuit Diagnosis >> Rear Air Control System >> Rear Air Control (Front) Diagnosis Procedure >> Diagnostic Procedure For Rear Air Control (Front)

Diagnostic Procedure For Rear Air Control (Front)

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM:

  1. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH
    1. With the rear blower motor set to maximum speed, rotate the rear temperature/mode control dial back and forth slowly between maximum heat and maximum cooling.
    2. Check for the tone of the air blowing from the rear vents to change, and for the air to move between the roof vents and the foot vents.

      Is the inspection result normal? 

      YES: Rear air control and air mix door (rear) are working properly. Refer to "COMPONENT FUNCTION CHECK " for insufficient cooling or "COMPONENT FUNCTION CHECK " for insufficient heating.

      NO: GO TO 2.

  2. CHECK AIR MIX DOOR MOTOR (REAR) POSITION BALANCED RESISTOR (PBR) FEEDBACK VOLTAGE
    1. Using CONSULT, check "RR FDBCK" in "DATA MONITOR" mode in "HVAC". Refer to "CONSULT FUNCTION (HVAC) ".
    2. Observe "RR FDBCK" voltage while rotating rear temperature control dial (front) between 32°C (90°F) and 18°C (60°F).
      Monitor Item Condition Results
      RR FDBCK Rotate rear temperature control dial (front) between maximum cold and maximum hot Voltage varies between 0.2 and 4.8V.

      Is the inspection result normal? 

      YES >>

      • Air mix door motor (rear) is OK.
      • Inspect air mix door (rear) for mechanical failure and repair if necessary.

      NO: GO TO 3.

  3. CHECK REAR AIR CONTROL (FRONT) POWER SUPPLY
    1. Turn ignition switch ON.
    2. Check voltage between rear air control (front) harness connector R2 terminal 10 and ground.

      Battery voltage should exist  .

      Is the inspection result normal? 

      YES: GO TO 4.

      NO: Repair harness or connector.

  4. CHECK REAR AIR CONTROL (FRONT) GROUND CIRCUIT
    1. Turn ignition switch OFF.
    2. Check continuity between rear air control (front) harness connector R2 terminal 1 and ground.

      Continuity should exist  .

      Is the inspection result normal? 

      YES: GO TO 5.

      NO: Repair harness or connector.

  5. CHECK REAR AIR CONTROL (FRONT) REFERENCE VOLTAGE
    1. Turn ignition switch ON.
    2. Check voltage between rear air control (front) harness connector R2 terminal 3 and ground.
      Connector Terminals Voltage (Approx.)
      (+) (-)
      Rear air control (front): R2 3 Ground 4.5V

      Is the inspection result normal? 

      YES: GO TO  7.

      NO: GO TO 6.

  6. CHECK REAR AIR CONTROL (FRONT) REFERENCE VOLTAGE CIRCUIT
    1. Disconnect A/C auto amp. and rear air control (front) connectors.
    2. Check continuity between A/C auto amp. harness connector M50 terminal 28 and rear air control (front) harness connector R2 terminal 3.

      Continuity should exist  .

      Is the inspection result normal? 

      YES: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

      NO: Repair harness or connector.

  7. CHECK REAR AIR CONTROL (FRONT) REFERENCE GROUND CIRCUIT
    1. Turn ignition switch OFF.
    2. Check continuity between rear air control (front) harness connector R2 terminal 8 and ground.

      Continuity should exist  .

      Is the inspection result normal? 

      YES: GO TO  9.

      NO: GO TO 8.

  8. CHECK REAR AIR CONTROL (FRONT) REFERENCE GROUND CIRCUIT FOR OPEN
    1. Disconnect A/C auto amp. connector and rear air control (front) harness connector.
    2. Check continuity between A/C auto amp. harness connector M49 terminal 3 and rear air control (front) harness connector R2 terminal 8.

      Continuity should exist  .

      Is the inspection result normal? 

      YES: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

      NO: Repair harness or connector.

  9. CHECK REAR AIR CONTROL (FRONT) AUX TEMP POT VOLTAGE
    1. Turn ignition switch ON.
    2. Check voltage between A/C auto amp. harness connector M50 terminal 37 and ground while turning knob between full cold and full hot.
      Connector Terminals Voltage (Approx.)
      (+) (-)
      A/C auto amp.: M50 37 Ground Varying between 0.1V and 4.9V

      Is the inspection result normal? 

      YES: GO TO  11.

      NO: GO TO 10.

  10. CHECK REAR AIR CONTROL (FRONT) AUX TEMP POT CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect A/C auto amp. connector and rear air control (front) connector.
    3. Check continuity between A/C auto amp. harness connector M50 terminal 37 and rear air control (front) harness connector R2 terminal 7.

      Continuity should exist  .

      Is the inspection result normal? 

      YES: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

      NO: Repair harness or connector.

  11. CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN AND SHORT TO GROUND
    1. Turn ignition switch OFF.
    2. Disconnect the A/C auto amp. harness connector M50 and the air mix door motor (rear) harness connector B155.
    3. Check continuity between A/C auto amp. harness connector M50 terminals 43, 44 and the air mix door motor (rear) harness connector B155 terminal 1, 6.
      Connector Terminal Connector Terminal Continuity
      M50 43 B155 1 Yes
      44 6
    4. Check continuity between A/C auto amp. harness connector M50 terminals 43, 44 and ground.
      Connector Terminal - Continuity
      M50 43 Ground No
      44

      Is the inspection result normal? 

      YES: GO TO 12.

      NO: Repair or replace harness as necessary.

  12. CHECK A/C AUTO AMP. FOR AIR MIX DOOR MOTOR (REAR) POWER AND GROUND
    1. Reconnect A/C auto amp. harness connector.
    2. Turn ignition switch ON.
    3. Rotate temperature control dial (rear) to maximum hot.
    4. Check voltage between A/C auto amp. harness connector M50 terminal 43 and terminal 44 while rotating temperature control dial (rear) to maximum cold and back to maximum heat.
      Connector Terminals Condition Voltage (Approx.)
      (+) (-)
      M50 43 44 Rotate rear temperature control dial (front) to maximum cold Battery voltage
      44 43 Rotate rear temperature control dial (front) to maximum heat Battery voltage

      Is the inspection result normal? 

      YES: GO TO 13.

      NO: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

  13. CHECK AIR MIX DOOR MOTOR (REAR) PBR CIRCUITS FOR OPEN AND SHORT TO GROUND
    1. Turn ignition switch OFF.
    2. Disconnect the A/C auto amp. harness connectors M49 and M50.
    3. Check continuity between A/C auto amp. harness connector M49 terminal 3 and M50 terminal 28 and air mix door motor (rear) harness connector B155 terminal 2, 3.
      Connector Terminal Connector Terminal Continuity
      M49 3 B155 2 Yes
      M50 28 3
    4. Check continuity between A/C auto amp. harness connector M49 terminal 3, M50 terminal 28 and ground.
      Connector Terminal - Continuity
      M49 3 Ground No
      M50 28

      Is the inspection result normal? 

      YES: GO TO 14.

      NO: Repair or replace harness as necessary.

  14. CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND
    1. Check continuity between A/C auto amp. harness connector M50 terminal 30 and air mix door motor (rear) harness connector B155 terminal 4.
      Connector Terminal Connector Terminal Continuity
      M50 30 B155 4 Yes
    2. Check continuity between A/C auto amp. harness connector M50 terminal 30 and ground.
      Connector Terminal - Continuity
      M50 30 Ground No

      Is the inspection result normal? 

      YES: GO TO 15.

      NO: Repair or replace harness as necessary.

  15. CHECK A/C AUTO AMP. FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK SIGNAL
    1. Reconnect A/C auto amp. harness connectors.
    2. Turn ignition switch ON.
    3. Check voltage between A/C auto amp. harness connector M49 terminal 3, and M50 terminal 28.
      Connector Terminals Connector Terminals Voltage (Approx.)
      (+) (-)
      M50 28 M49 3 5V
    4. Check voltage between A/C auto amp. harness connector M50 terminal 30 and ground.
      Connector Terminal - Voltage (Approx.)
      M50 30 Ground 0V

      Is the inspection result normal? 

      YES: GO TO 16.

      NO: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

  16. CHECK A/C AUTO AMP. FOR FEEDBACK SIGNAL
    1. Reconnect the air mix door motor (rear) harness connector B155.
    2. Check voltage between A/C auto amp. harness connector M50 terminal 30 and ground.
      Connector Terminal - Voltage (Approx.)
      M50 30 Ground 0.1 to 4.9V

      Is the inspection result normal? 

      YES: Inspect air mix door (rear) for binding or mechanical failure. If air mix door (rear) moves freely, replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".

      NO: Replace the air mix door motor (rear). Refer to "REMOVAL AND INSTALLATION ".

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