2004 INFINITI QX56 ignition

TROUBLE DIAGNOSIS
ATC-51
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
Front Air Control Terminals and Reference ValueEJS002C9
Measure voltage between each terminal and ground by following
Terminals and Reference Value for Front Air Control.
PIN CONNECTOR TERMINAL LAYOUT
TERMINALS AND REFERENCE VALUE FOR FRONT AIR CONTROL
WJIA0759E
WJIA0402E
Te r m i -
nal No.Wire
colorItemIgnition
switchConditionVoltage (V)
(Approx.)
1 B Ground - - 0V
2YPower supply for each door motor
PBRON - 0 - 5V
3 W/G Air mix door motor (Driver) CW ON Clockwise rotation Battery voltage
4 G Air mix door motor (Driver) CCW ON Counterclockwise rotation Battery voltage
5 BR/W Mode door motor CW ON Clockwise rotation Battery voltage
6 P/L Mode door motor CCW ON Counterclockwise rotation Battery voltage
7 O Intake door motor CCW ON Counterclockwise rotation Battery voltage
8 G/B Intake door motor CW ON Clockwise rotation Battery voltage
9 L/B Intake sensor ON - 0 - 5V
10 L/R Fan ON signal ONFan switch OFF 5V
Fan switch ON 0V
11 Y/B Rear defroster request ON - Battery voltage
12 W/R Compressor ON signal ONA/C switch OFF 5V
A/C switch ON 0V
13 G/R Variable blower control ON - 0 - 5V
14 Y/G Power supply for IGN ON - Battery voltage
15 P Ground for each door motor PBR ON - 0 - 5V
16 GR Mode door motor PBR feedback ON - 0 - 5V
17 P Ambient sensor ON - 0 - 5V
18 SBAir mix door motor (Driver) PBR
feedbackON - 0 - 5V
19 LG Defroster door motor CW ON Clockwise rotation Battery voltage
20 P/B Defroster door motor CCW ON Counterclockwise rotation Battery voltage

ATC-52
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
21 V/R Sensor ground ON - 0 - 5V
22 Y/R Power supply for BAT - - Battery voltage
23 R/L Power supply for illumination ON Park lamps ON Battery voltage
24 BR Illumination ground - Park lamps ON
25 LG/B Defroster door motor feedback ON - 0 - 5V
26 R/B Front blower motor request ONFront blower motor OFF Battery voltage
Front blower motor ON 0V
27 GR/R Air mix door motor (Rear) CW ON Clockwise rotation Battery voltage
28 L/Y Air mix door motor (Rear) CCW ON Counterclockwise rotation Battery voltage
29 W/G Water valve ONWater valve open 0V
Water valve closed 5V
31 W/V Optical sensor (Passenger) ON - 0 - 5V
32 LG/R In-vehicle sensor signal ON - 0 - 5V
33 V Air mix door motor (Rear) set point ON - 0 - 5V
34 W CAN-H ON - -
35 R CAN-L ON - -
36 G/W Air mix door motor (Passenger) CW ON Clockwise rotation Battery voltage
37 LAir mix door motor (Passenger)
CCWON Counter clockwise rotation Battery voltage
38 W/L Rear blower motor request ONRear blower motor OFF Battery voltage
Rear blower motor ON 0V
39 Y/B Rear select signal ON - 0 - 5V
40 G/O Optical sensor (Driver) ON - 0 - 5V
41 R/WAir mix door motor (Passenger) PBR
feedbackON - 0 - 5V
42 R/YAir mix door motor (Rear) PBR feed-
backON - 0 - 5V
43 BR/Y In-vehicle sensor motor (power) ON - Battery voltage
44 O/B In-vehicle sensor motor (ground) ON - 0V Te r m i -
nal No.Wire
colorItemIgnition
switchConditionVoltage (V)
(Approx.)
PIIA2344E

ATC-56
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Operational Check (Front)EJS002CB
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 90°F or 32°C.
2. Press OFF switch [hold fan (down) switch down until system
shuts OFF].
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera-
ture.
7. Press OFF switch [hold fan (down) switch down until system
shuts OFF].
If NG, go to trouble diagnosis procedure for ATC-121, "
Memory
Function" .
If OK, continue with next check.
CHECKING BLOWER
1. Press fan (up) switch. Blower should operate on low speed. The
front blower speed symbol should have one bar lit (on display).
2. Press fan (up) switch again, and continue checking blower
speed and blower symbol until all speeds are checked.
3. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for AT C - 8 5 , "
DIAGNOSTIC
PROCEDURE FOR BLOWER MOTOR" .
If OK, continue with next check.Conditions : Engine running and at normal operating temperature
WJIA0404E
WJIA0411E
WJIA0404E
WJIA0405E

ATC-62
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
1. CHECK POWER SUPPLY CIRCUITS FOR FRONT AIR CONTROL
1. Disconnect front air control connector M49.
2. Check voltage between front air control harness connector M49
terminals 14 (Y/G) and 22 (Y/R), and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A fuses [No. 8 and 19, located in the fuse block (J/B)]. Refer to PG-76, "
FUSE BLOCK-
JUNCTION BOX(J/B)" .

If fuses are OK, check harness for open circuit. Repair or replace as necessary.

If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as neces-
sary.
2. CHECK GROUND CIRCUIT FOR FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Check continuity between front air control harness connector
M49 terminal 1 (B) and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.
Terminals Ignition switch position
(+)
(-) OFF ACC ON Front air
control
connectorTerminal No.
(Wire color)
M4914 (Y/G)
GroundApprox. 0V Approx. 0VBattery
voltage
22 (Y/R)Battery
voltageBattery
voltageBattery
voltage
WJIA0415E
1 - Ground : Continuity should exist.
WJIA0964E

TROUBLE DIAGNOSIS
ATC-65
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: August 20072004 QX56
COMPONENT DESCRIPTION
Mode Door Motor
The mode door motor is attached to the heater & cooling unit. It
rotates so that air is discharged from the outlet as indicated by the
front air control. Motor rotation is conveyed to a link which activates
the mode door.
DIAGNOSTIC PROCEDURE FOR MODE DOOR MOTOR
1. CHECK RESULT FROM FRONT AIR CONTROL SELF-DIAGNOSIS
Self-diagnosis code 92 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 AND GROUND CIRCUITS FOR MODE DOOR MOTOR
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49 and mode door
motor connector M142.
3. Check continuity between front air control harness connector
M49 terminal 5 (BR/W) and mode door motor connector M142
terminal 5 (BR/W) and between front air control harness con-
nector M49 terminal 6 (P/L) and mode door motor connector
M142 terminal 6 (P/L).
OK or NG
OK >> Replace mode door motor. Refer to ATC-152, "Removal and Installation" .
NG >> Repair or replace harness as necessary.
3. CHECK PBR REFERENCE SIGNAL VOLTAGE
1. Disconnect mode door motor connector M142.
2. Turn ignition switch ON.
3. Check voltage between mode door motor harness connector
M142 terminal 3 (Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
WJIA0587E
5 - 5 : Continuity should exist.
6 - 6 : Continuity should exist.
LJIA0027E
3 - Ground : Approx. 5V
LJIA0028E

ATC-66
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
4. CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN MODE DOOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between mode door motor harness connector
M142 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 mode door motor harness connector
M142 terminal 1 (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 mode door motor connector.
2. Turn ignition switch ON.
3. Check voltage between front air control harness connector M49
terminal 16 (GR) and ground.
4. Press mode switch through all modes.
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 mode door motor connector M142 and front air con-
trol harness connector M49.
3. Check continuity between mode door motor harness connector
M142 terminal 2 (GR) and front air control harness connector
M49 terminal 16 (GR).
OK or NG
OK >> Replace mode door motor. Refer to ATC-152, "MODE
DOOR MOTOR" .
NG >> Repair or replace harness as necessary.3 - 2 : Continuity should exist.
LJIA0029E
1 - 15 : Continuity should exist.
LJIA0031E
16 - Ground : Approx. 0 - 5V
LJIA0032E
2 - 16 : Continuity should exist.
LJIA0034E

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