2004 INFINITI QX56 turn signal

ATC-68
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:

Front air control

Air mix door motors (driver, passenger, and rear)

PBR (built-into air mix door motors)

In-vehicle sensor

Ambient sensor

Optical sensor

Intake sensor
System Operation
The front air control receives data from the temperature selected by the driver side, passenger side, and rear.
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 con-
trol monitors the air mix door positions by measuring the voltage signal on the PBR circuits of each door.
In AUTO mode the air mix, intake, mode door, and defrost door positions are set by the front air control which
determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor,
intake sensor, and the temperature selected by the driver and front and rear passengers.
Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new
door position data is returned to the front air control.
Air Mix Door Control Specification
WJIA0427E
WJIA0435E

ATC-70
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
2. CHECK POWER SUPPLY CIRCUITS FOR AIR MIX DOOR MOTOR (DRIVER)
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49 and air mix door
motor (Driver) connector M147.
3. Check continuity between front air control harness connector
M49 terminal 3 (W/G) and 4 (G) and air mix door motor (Driver)
harness connector M147 terminal 1 (W/G) and 6 (G).
OK or NG
OK >> Replace air mix door motor (Driver). Refer to ATC-153,
"FRONT AIR MIX DOOR MOTOR (DRIVER)" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Driver) connector M147.
3. Turn ignition switch ON.
4. Check voltage between air mix door motor (Driver) harness con-
nector M147 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR (DRIVER) AND
FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Driver) harness
connector M147 terminal 3 (Y) and front air control harness con-
nector M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Driver) harness
connector M147 terminal 2 (P) and front air control harness con-
nector M49 terminal 15 (P).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness as necessary.3 - 1 : Continuity should exist.
4 - 6 : Continuity should exist.
WJIA0588E
3 - Ground : Approx. 5V
LJIA0038E
3 - 2 : Continuity should exist.
LJIA0039E
2 - 15 : Continuity should exist.
WJIA0589E

TROUBLE DIAGNOSIS
ATC-71
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
6. CHECK PBR FEEDBACK SIGNAL
1. Reconnect front air control connector and air mix door motor
(Driver) connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 18 (SB) and ground.
4. Rotate temperature dial (Driver) through complete range.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7.
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Driver) connector M147 and
front air control connector M49.
3. Check continuity between air mix door motor (Driver) harness
connector M147 terminal 4 (SB) and front air control harness
connector M49 terminal 18 (SB).
OK or NG
OK >> Replace air mix door motor (Driver). Refer to ATC-153,
"FRONT AIR MIX DOOR MOTOR (DRIVER)" .
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (PASSENGER)
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 12 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR AIR MIX DOOR MOTOR (PASSENGER)
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50 and air mix door
motor (Passenger) connector M143.
3. Check continuity between front air control harness connector
M50 terminal 36 (G/W) and 37 (L) and air mix door motor (Pas-
senger) connector M143 terminal 1 (G/W) and 6 (L).
OK or NG
OK >> Replace air mix door motor (Passenger). Refer to AT C -
154, "FRONT AIR MIX DOOR MOTOR (PASSENGER)" .
NG >> Repair or replace harness as necessary.18 - Ground : Approx. 0V - 5V
LJIA0041E
4 - 18 Continuity should exist.
WJIA0590E
36 - 1 Continuity should exist.
37 - 6 Continuity should exist.
WJIA0548E

ATC-72
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Passenger) connector M143.
3. Turn ignition switch ON.
4. Check voltage between air mix door motor (Passenger) harness
connector M143 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR (PASSENGER) AND
FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 terminal 3 (Y) and front air control harness
connector M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 terminal 2 (P) and front air control harness
connector M49 terminal 15 (P).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL
1. Reconnect front air control connector and air mix door motor
(Passenger) connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50
terminal 41 (R/W) and ground.
4. Rotate temperature dial (Passenger) through complete range.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7. 3 - Ground : Approx.5V
LJIA0044E
3 - 2 Continuity should exist.
LJIA0045E
2 - 15 Continuity should exist.
WJIA0549E
41 - Ground : Approx. 0 - 5V
LJIA0047E

TROUBLE DIAGNOSIS
ATC-73
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Passenger) connector M143 and
front air control connector M50.
3. Check continuity between air mix door motor (Passenger) har-
ness connector M143 terminal 4 (R/W) and front air control har-
ness connector M50 terminal 41 (R/W).
OK or NG
OK >> Replace air mix door motor (Passenger). Refer to AT C -
154, "FRONT AIR MIX DOOR MOTOR (PASSENGER)"
.
NG >> Repair or replace harness as necessary.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR)
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 38 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR AIR MIX DOOR MOTOR (REAR)
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50 and air mix door
motor (Rear) connector B155.
3. 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).
OK or NG
OK >> Replace air mix door motor (Rear). Refer to ATC-154, "REAR AIR MIX DOOR MOTOR" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect air mix door motor (Rear) connector B155.
3. Turn ignition switch ON.
4. Check voltage between air mix door motor (Rear) harness con-
nector B155 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.4 - 41 : Continuity should exist.
WJIA0550E
27 - 1 Continuity should exist.
28 - 6 Continuity should exist.
LJIA0049E
3 - Ground : Approx. 5V
LJIA0050E

ATC-74
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR (REAR) AND
FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Rear) harness
connector B155 terminal 3 (Y) and front air control harness con-
nector M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between air mix door motor (Rear) harness
connector B155 terminal 2 (P) and front air control harness con-
nector M49 terminal 15 (P).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL
1. Reconnect front air control connector and air mix door motor
(Rear) connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M50
terminal 42 (R/Y) and ground.
4. Rotate rear temperature/mode dial (Front) through complete
range.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7.3 - 2 Continuity should exist.
LJIA0051E
2 - 15 Continuity should exist.
LJIA0052E
42 - Ground : Approx. 0 - 5V
LJIA0053E

TROUBLE DIAGNOSIS
ATC-81
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 62 is present. Refer to ATC-53, "
A/C System Self-diagnosis Function" .
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. CHECK POWER SUPPLY CIRCUIT FOR DEFROSTER DOOR MOTOR
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49 and defroster door
motor connector M144.
3. Check continuity between front air control harness connector
M49 terminal 19 (LG) and defroster door motor harness connec-
tor M144 terminal 1 (LG) and between front air control harness
connector M49 terminal 20 (P/B) and defroster door motor con-
nector M144 terminal 6 (P/B).
OK or NG
OK >> Replace defroster door motor. Refer to ATC-150, "Removal and Installation" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Disconnect defroster door motor harness connector M144.
2. Turn ignition switch ON.
3. Check voltage between defroster door motor harness connector
M144 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN DEFROSTER DOOR MOTOR AND FRONT
AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 3 (Y) and front air control harness connector
M49 terminal 2 (Y).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair or replace harness as necessary.19 - 1 : Continuity should exist.
20 - 6 : Continuity should exist.
WJIA0553E
3 - Ground : Approx. 5V
WJIA0554E
3 - 2 : Continuity should exist.
WJIA0555E

ATC-82
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
5. CHECK PBR GROUND REFERENCE CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 2 (P) and front air control harness connector
M49 terminal 15 (P).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness as necessary.
6. CHECK PBR FEEDBACK SIGNAL
1. Reconnect front air control connector and defroster door motor
connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 25 (LG/B) and ground.
4. Change mode between floor, defroster, and panel.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> GO TO 7.
7. CHECK PBR FEEDBACK CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect defroster door motor connector M144 and front air
control connector M49.
3. Check continuity between defroster door motor harness connec-
tor M144 terminal 4 (LG/B) and front air control harness connec-
tor M49 terminal 25 (LG/B).
OK or NG
OK >> Replace defroster door motor. Refer to ATC-150,
"Removal and Installation" .
NG >> Repair or replace harness as necessary.2 - 15 : Continuity should exist.
WJIA0556E
25 - Ground : Approx. 0 - 5V
WJIA0770E
4 - 25 : Continuity should exist.
WJIA0558E