Manual Air Conditioner: Overview Nissan Armada I

A/C IDENTIFICATION LABEL

Vehicles with factory installed fluorescent dye have this identification label on the underside of hood.

Scheme 1

DESCRIPTION

The front air control provides regulation of the vehicle's interior temperature. The system is based on the position of the front air controls temperature switch selected by the driver. This is done by utilizing a microcomputer, also referred to as the front air control, which receives input signals from the following two sensors

1. Intake sensor
2. PBR (Position Balanced Resistor).

The front air control uses these signals (including the set position of the temperature switch) to control

1. Outlet air volume
2. Air temperature
3. Air distribution

The front air control also provides separate regulation of the vehicle's interior temperature for the rear passenger area. The system is based on the temperature and rear blower settings selected from rear control switches located on the front air control, or from the temperature and rear blower settings selected from rear control switches on the rear air control, when the front air control switches are set to the rear position.

The front air control is used to select

1. Outlet air volume
2. Air temperature/distribution

DESCRIPTION OF CONTROL SYSTEM

The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.

The relationship of these components is shown in the figure below

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CAN COMMUNICATION SYSTEM DESCRIPTION

Refer to CAN COMMUNICATION.

CONSULT-II BASIC OPERATION

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1. With the ignition switch OFF, connect CONSULT-II and CONSULT-II CONVERTER to the data link connector, and turn the ignition switch ON.
2. Touch "START (NISSAN BASED VHCL)".
3. Touch "HVAC" on "SELECT SYSTEM" screen. If "HVAC" is not indicated, go to «CONSULT-II DATA LINK CONNECTOR (DLC) CIRCUIT»(ref-233237-S35323486542006052500000).

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1. Touch "SELF-DIAG RESULTS" on "SELECT DIAG MODE" screen to view all set DTC's.

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1. Touch "DATA MONITOR" on "SELECT DIAG MODE" screen.
2. Touch either "MAIN SIGNALS" or "SELECTION FROM MENU" on "DATA MONITOR" screen. DTC DESCRIPTION All signals Monitors all the items. Selection from menu Selects and monitors the individual item selected.
3. When "SELECTION FROM MENU" is selected, touch items to be monitored. When "MAIN SIGNALS" is selected, all the items will be monitored.
4. Touch "START".
5. Touch "RECORD" while monitoring, then the status of the monitored item can be recorded. To stop recording, touch "STOP".

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1. With the ignition switch OFF, connect CONSULT-II and CONSULT-II CONVERTER to the data link connector, and turn the ignition switch ON.
2. Touch "START (NISSAN BASED VHCL)".
3. Touch "BCM" on "SELECT SYSTEM" screen. If "BCM" is not indicated, go to «CONSULT-II DATA LINK CONNECTOR (DLC) CIRCUIT»(ref-233237-S35323486542006052500000).

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1. Touch "AIR CONDITIONER" on "SELECT TEST ITEM" screen.
2. Touch "DATA MONITOR" on "SELECT DIAG MODE" screen.
3. Touch either "ALL SIGNALS" or "SELECTION FROM MENU" on "DATA MONITOR" screen. SIGNALS REFERENCE All Signals Monitors all the items. Selection from menu Selects and monitors the individual item selected.
4. When "SELECTION FROM MENU" is selected, touch items to be monitored. When "ALL SIGNALS" is selected, all the items will be monitored.
5. Touch "START".
6. Touch "RECORD" while monitoring, then the status of the monitored item can be recorded. To stop recording, touch "STOP".

OPERATIONAL CHECK (FRONT)

The purpose of the operational check is to confirm that the system operates properly.

1. Conditions: Engine running and at normal operating temperature

OPERATIONAL CHECK (REAR)

The purpose of the operational check is to confirm that the system operates properly.

1. Conditions: Engine running and at normal operating temperature

SYSTEM OPERATION

The mode door position (vent, B/L, foot, and defrost) is set by the front air control by means of the mode door motor. When a mode door position is selected on the front air control, voltage is applied to one circuit of the mode door motor while ground is applied to the other circuit, causing the mode door motor to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The front air control monitors the mode door position by measuring the voltage signal on the PBR circuit.

The front air control receives data from the temperature selected by the driver and rear passenger. The front air control then applies a voltage to one circuit of the appropriate air mix door motor, while ground is applied to the other circuit, causing the appropriate air mix door motor to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The front air control monitors the air mix door positions by measuring the voltage signal on the PBR circuits of each door.

Scheme 16

The front air mix door motor is attached to the front heater & cooling unit. The rear air mix door motor is attached to the rear heater & cooling unit. These motors rotate so that the air mix door is opened or closed to a position set by the front (or rear) air control. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the front air control by the PBR built into the air mix door motors.

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1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS Self-diagnosis DTC B2577 is present. Refer to «SELF-DIAGNOSIS»(ref-233308-S23606142312006052500000). YES or NO YES: GO TO 2. NO: GO TO 3.
2. CHECK POWER SUPPLY CIRCUITS FOR AIR MIX DOOR MOTOR (FRONT) Turn ignition switch OFF. Disconnect front air control connector and air mix door motor (front) connector. Check continuity between front air control harness connector M49 terminal 3 (W/G) and 4 (G) and air mix door motor (front) harness connector M147 terminal 1 (W/G) and 6 (G). 3 - 1: Continuity should exist. 4 - 6: Continuity should exist. OK or NG OK: Replace air mix door motor (front). Refer to «FRONT AIR MIX DOOR MOTOR»(ref-233308-S18846638812006052500000). NG: Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE Turn ignition switch OFF. Disconnect the air mix door motor (front) connector. Turn ignition switch ON. Check voltage between air mix door motor (front) harness connector M147 terminal 3 (Y) and ground. 3 - Ground: Approx. 5 V OK or NG OK: GO TO 5 . NG: GO TO 4 .
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR (FRONT) AND FRONT AIR CONTROL Turn ignition switch OFF. Disconnect the front air control connector. Check continuity between air mix door motor (front) harness connector M147 terminal 3 (Y) and front air control harness connector M49 terminal 2 (Y). 3 - 2: Continuity should exist. OK or NG OK: Replace front air control. Refer to «FRONT AIR CONTROL»(ref-233308-S27882370372006052500000). NG: Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT Turn ignition switch OFF. Disconnect the front air control connector. Check continuity between air mix door motor (front) harness connector M147 terminal 2 (P) and front air control harness connector M49 terminal 15 (P). 2 - 15: Continuity should exist. OK or NG OK: GO TO 6 . NG: Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL Reconnect the front air control connector and air mix door motor (front) connector. Turn ignition switch ON. Check voltage between front air control harness connector M49 terminal 18 (SB) and ground. Rotate front temperature control dial through complete range. 18 - Ground: Approx. 0 V - 5 V OK or NG OK: Replace front air control. Refer to «FRONT AIR CONTROL»(ref-233308-S27882370372006052500000). NG: GO TO 7.
7. CHECK PBR FEEDBACK CIRCUIT Turn ignition switch OFF. Disconnect the air mix door motor (front) connector and front air control connector. Check continuity between air mix door motor (front) harness connector M147 terminal 4 (SB) and front air control harness connector M49 terminal 18 (SB). 4 - 18 Continuity should exist. OK or NG OK: Replace air mix door motor (front). Refer to «FRONT AIR MIX DOOR MOTOR»(ref-233308-S18846638812006052500000). NG: Repair or replace harness as necessary.

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1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS Self-diagnosis DTC B257A is present. Refer to «SELF-DIAGNOSIS»(ref-233308-S23606142312006052500000). YES or NO YES: GO TO 2. NO: GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR AIR MIX DOOR MOTOR (REAR) Turn ignition switch OFF. Disconnect front air control connector and air mix door motor (rear) connector. Check continuity between front air control harness connector M50 terminal 27 (GR/R) and air mix door motor (rear) harness connector B155 terminal 1 (GR/R) and between front air control harness connector M50 terminal 28 (L/Y) and air mix door motor (rear) harness connector B155 terminal 6 (L/Y). 27 - 1 Continuity should exist. 28 - 6 Continuity should exist. OK or NG OK: Replace air mix door motor (Rear). Refer to «REAR AIR MIX DOOR MOTOR»(ref-233308-S15983864102006052500000). NG: Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE Turn ignition switch OFF. Disconnect the air mix door motor (rear) connector. Turn ignition switch ON. Check voltage between air mix door motor (rear) harness connector B155 terminal 3 (Y) and ground. 3 - Ground: Approx. 5 V OK or NG OK: GO TO 5 . NG: GO TO 4 .
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR (REAR) AND FRONT AIR CONTROL Turn ignition switch OFF. Disconnect the front air control connector. Check continuity between air mix door motor (rear) harness connector B155 terminal 3 (Y) and front air control harness connector M49 terminal 2 (Y). 3 - 2 Continuity should exist. OK or NG OK: Replace front air control. Refer to «FRONT AIR CONTROL»(ref-233308-S27882370372006052500000). NG: Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT Turn ignition switch OFF. Disconnect the front air control connector. Check continuity between air mix door motor (rear) harness connector B155 terminal 2 (P) and front air control harness connector M49 terminal 15 (P). 2 - 15 Continuity should exist. OK or NG OK: GO TO 6 . NG: Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL Reconnect the front air control connector and air mix door motor (rear) connector. Turn ignition switch ON. Check voltage between front air control harness connector M50 terminal 42 (R/Y) and ground. Rotate rear temperature control dial through complete range. 42 - Ground: Approx. 0 - 5 V OK or NG OK: Replace front air control. Refer to «FRONT AIR CONTROL»(ref-233308-S27882370372006052500000). NG: GO TO 7.
7. CHECK PBR FEEDBACK CIRCUIT Turn ignition switch OFF. Disconnect the air mix door motor (rear) connector and front air control connector. Check continuity between air mix door motor (rear) harness connector B155 terminal 4 (R/Y) and front air control harness connector M50 terminal 42 (R/Y). 4 - 42 Continuity should exist. OK or NG OK: Replace air mix door motor (Rear). Refer to «REAR AIR MIX DOOR MOTOR»(ref-233308-S15983864102006052500000). NG: Repair or replace harness as necessary.

The intake door control determines the intake door positions based on the position of the recirculation switch. When the recirculation switch is depressed the intake door motor rotates closing off the fresh air inlet and recirculating the cabin air. If the recirculation switch is depressed again, the intake door motor rotates in the opposite direction, again allowing fresh air into the cabin.

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The front air control determines defroster door position based on the position of the mode switch. When the mode switch is in the defroster position, the defroster door motor rotates directing air to the defroster ducts. When any mode other than defroster is selected, the defroster motor rotates in the opposite direction closing off air flow to the defroster ducts.

SYSTEM DESCRIPTION

The front air control controls compressor operation based on ambient and intake temperature and a signal from ECM.

BREAK-IN OPERATION

When replacing compressor clutch assembly, always conduct the break-in operation. This is done by engaging and disengaging the clutch about 30 times. Break-in operation raises the level of transmitted torque.

See also:
• DTC P0125 ECT SENSOR