Mode Door Motor (Front) Diagnosis Procedure
Regarding Wiring Diagram information, refer to "WIRING DIAGRAM ".
SYMPTOM:
- Air outlet does not change.
- Mode door motor does not operate normally.
- CHECK MODE DOOR MOTOR (FRONT) POSITION BALANCED RESISTOR (PBR) FEEDBACK VOLTAGE
- Turn ignition switch ON.
- Using CONSULT, check "MODE FDBCK" in "DATA MONITOR" mode in "HVAC". Refer to "CONSULT FUNCTION (HVAC) ".
- Observe "MODE FDBCK" voltage while cycling A/C auto amp mode switch through all modes.
Monitor Item Condition Results MODE FDBCK Cycle mode switch through all modes, D/F ( ), VENT (
), B/L (
), and FOOT(
)
Voltage varies between D/F ( ) and VENT (
), and between VENT (
) and B/L (
).
Is the inspection result normal?
YES:
- Mode door motor is OK.
- Inspect mode door (front) for mechanical failure. Refer to "COMPONENTS ".
NO: GO TO 2.
- CHECK MODE DOOR MOTOR (FRONT) CIRCUITS FOR OPEN AND SHORT TO GROUND
- Turn ignition switch OFF.
- Disconnect the A/C auto amp. harness connector M49 (A) and the mode door motor (front) harness connector M142 (B).
- Check continuity between A/C auto amp. harness connector M49 (A) terminals 19, 20 and the mode door motor harness connector M142 (B) terminals 5, 6.
A B Continuity Connector Terminal Connector Terminal M49 19 M142 5 Yes 20 6 - Check continuity between A/C auto amp. harness connector M49 terminals 19, 20 and ground.
Connector Terminal - Continuity M49 19 Ground No 20 Courtesy of NISSAN NORTH AMERICA, INC.
Is the inspection result normal?
YES: GO TO 3.
NO: Repair or replace harness as necessary.
- CHECK A/C AUTO AMP. FOR MODE DOOR MOTOR (FRONT) POWER AND GROUND
- Reconnect A/C auto amp. harness connector.
- Turn ignition switch ON.
- Press the mode switch to the D/F (
) mode.
- Check voltage between A/C auto amp. harness connector M49 terminal 19 and terminal 20 while pressing the mode switch to the VENT (
), and then the B/L (
) mode.
Connector Terminals Condition Voltage (Approx.) (+) (-) M49 19 20 D/F ( ) mode to VENT (
) mode
Battery voltage 20 19 VENT ( ) mode to B/L (
) mode
Battery voltage Courtesy of NISSAN NORTH AMERICA, INC.
Is the inspection result normal?
YES: GO TO 4.
NO: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".
- CHECK MODE DOOR MOTOR (FRONT) PBR CIRCUITS FOR OPEN AND SHORT TO GROUND
- Turn ignition switch OFF.
- Disconnect the A/C auto amp. harness connectors.
- Check continuity between A/C auto amp. harness connector M49 (C) terminal 3, and M50 (A) terminal 28 and the mode door motor harness connector M142 (B) terminals 1, 3.
A and C B Continuity Connector Terminal Connector Terminal M49 (C) 3 M142 3 Yes M50 (A) 28 1 - Check continuity between A/C auto amp. harness connector M49 (C) terminal 3, M50 (A) terminal 28 and ground.
Connector Terminal - Continuity M49 (C) 3 Ground No M50 (A) 28 Is the inspection result normal?
YES: GO TO 5.
NO: Repair or replace harness as necessary.
- CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND
- Check continuity between A/C auto amp. harness connector M49 (A) terminal 7 and mode door motor harness connector M142 (B) terminal 2.
A B Continuity Connector Terminal Connector Terminal M49 7 M142 2 Yes - Check continuity between A/C auto amp. harness connector M49 terminal 7 and ground.
Connector Terminal - Continuity M49 7 Ground No Courtesy of NISSAN NORTH AMERICA, INC.
Is the inspection result normal?
YES: GO TO 6.
NO: Repair or replace harness as necessary.
- Check continuity between A/C auto amp. harness connector M49 (A) terminal 7 and mode door motor harness connector M142 (B) terminal 2.
- CHECK A/C AUTO AMP. FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK SIGNAL
- Reconnect A/C auto amp. harness connectors.
- Turn ignition switch ON.
- Check voltage between A/C auto amp. harness connector M49 (B) terminal 3, and M50 (A) terminal 28.
A B Connector Terminals Connector Terminals Voltage (Approx.) (+) (-) M50 28 M49 3 5 Volts - Check voltage between A/C auto amp. harness connector M49 terminal 7 and ground.
Connector Terminal - Voltage (Approx.) M49 7 Ground 0 Volts Courtesy of NISSAN NORTH AMERICA, INC.
Is the inspection result normal?
YES: GO TO 7.
NO: Replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".
- CHECK A/C AUTO AMP. FOR FEEDBACK SIGNAL
- Reconnect the mode door motor (front) harness connector M142.
- Check voltage between A/C auto amp. harness connector M49 terminal 7 and ground.
Connector Terminal - Voltage (Approx.) M49 7 Ground 0.2 to 4.8 Volts Courtesy of NISSAN NORTH AMERICA, INC.
Is the inspection result normal?
YES: Inspect mode door (front) for binding or mechanical failure. If mode door moves freely, replace A/C auto amp. Refer to "REMOVAL AND INSTALLATION ".
NO: Replace the mode door motor (front). Refer to "REMOVAL AND INSTALLATION ".