INFINITI QX56 2006 Factory Service Manual

ATC-130
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Self-diagnosisEJS003XZ
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1ATC-61, "Power Supply and Ground
Circuit for Front Air Control"
*2 ATC-134, "Ambient Sensor Circuit"*3ATC-140, "In-vehicle Sensor"
*4ATC-140, "Optical Sensor Circuit"*5 ATC-142, "Intake Sensor Circuit"*6AT C - 7 0 , "Air Mix Door Motor Circuit"
*7ATC-58, "Operational Check (Front)"*8 ATC-39, "SYMPTOM TABLE"
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TROUBLE DIAGNOSISATC-131
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Revision: November 2009 2006 QX56
Memory FunctionEJS003Y0
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
*1AT C - 6 1 , "Power Supply and Ground
Circuit for Front Air Control"
*2ATC-58, "Operational Check (Front)"*3 AT C - 5 6 , "A/C System Self-diagnosis
Function"
*4AT C - 5 7 , "SELF-DIAGNOSIS CODE
CHART"
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ATC-132
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Water Valve CircuitEJS003Y1
COMPONENT DESCRIPTION
Water Valve
The water valve (1) cuts the flow of engine coolant to the front and
rear heater cores to allow for maximum cooling during A/C opera-
tion. It is controlled by the front air control.
DIAGNOSTIC PROCEDURE FOR WATER VALVE
1. CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Disconnect water valve connector F68.
2. Turn ignition switch ON.
3. Rotate temperature control dial (driver) to 32 °C (90 °F).
4. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 16 °C (60 °F).
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 1 and front air control harness connector M50 (B)
terminal 29.
4. Check continuity between water valve harness connector F68 (A) terminal 1 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
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Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 1 2Rotate temperature
control dial Battery
voltage
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1 - 29 : Continuity should exist.
1 - Ground : Continuity should not exist.
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TROUBLE DIAGNOSISATC-133
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Revision: November 2009 2006 QX56
3. CHECK WATER VALVE POWER AND GROUND CIRCUITS
1. Rotate temperature control dial (driver) to 16 °C (60 °F).
2. Check voltage between water valve harness connector F68 ter- minal 1 and terminal 2 while rotating temperature control dial
(driver) to 32 °C (90 °F).
OK or NG
OK >> Replace the water valve.
NG >> GO TO 4.
4. CHECK WATER VALVE CONTROL OUTPUT CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front air control connector M50.
3. Check continuity between water valve harness connector F68 (A) terminal 2 and front air control harness connector M50 (B)
terminal 30.
4. Check continuity between water valve harness connector F68 (A) terminal 2 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
NG >> Repair harness or connector.
Connector Terminals
Condition Voltage
(Approx.)
(+) (-)
Water valve: F68 2 1Rotate temperature
control dial Battery
voltage
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2 - 30 : Continuity should exist.
2 - Ground : Continuity should not exist.
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ATC-134
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Ambient Sensor CircuitEJS003Y2
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a value
which is then input into the front air control.
AMBIENT TEMPERATURE INPUT PROCESS
The front air control includes a processing circuit for the ambient sensor input. However, when the tempera-
ture detected by the ambient sensor increases quickly, the processing circuit retards the front air control func-
tion. It only allows the front air control to recognize an ambient temperature increase of 0.33°C (0.6 °F) per 100
seconds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by the ambient sensor
will increase. This is because the heat from the engine compartment can radiate to the front grille area, loca-
tion of the ambient sensor.
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. Using the
CONSULT-II, DTC B257B or B257C is displayed. Without a CON-
SULT-II, code 40 or 41 is indicated on front air control as a result of
conducting the front air control self-diagnosis.
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E1 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
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1 - Ground : Approx. 5V
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TROUBLE DIAGNOSISATC-135
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Revision: November 2009 2006 QX56
2. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between ambient sensor harness connector E1 terminal 1 and front air control harness connector M49 termi-
nal 17.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to ATC-134, "
Ambient Sensor Circuit" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL"
2. Go to AT C - 5 6 , "A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace ambient sensor. Refer to ATC-145, "
AMBIENT SENSOR" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between ambient sensor harness connector E1 terminal 2 and front air control harness connector M49 termi-
nal 21.
4. Check continuity between ambient sensor harness connector E1 terminal 2 and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL"
2. Go to self-diagnosis AT C - 5 6 , "A/C System Self-diagnosis Function" and perform self-diagno-
sis.
NG >> Repair harness or connector. 1 - 17
: Continuity should exist.
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2 - 21: Continuity should exist.
2 - Ground : Continuity should not exist.
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ATC-136
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor (1) connector E1, measure
resistance between terminals 1 and 2 at sensor component side,
using the table below.
If NG, replace ambient sensor.
Temperature °C (°F) Resistance kΩ
− 15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27
45 (113) 1.07
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TROUBLE DIAGNOSISATC-137
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AT C
Revision: November 2009 2006 QX56
In-vehicle Sensor CircuitEJS003Y3
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on cluster lid D. It converts varia-
tions in temperature of passenger compartment air (drawn in through
the integrated fan) into a resistance value. It is then input into the
front air control.
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ATC-138
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
DIAGNOSTIC PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted. Using the
CONSULT-II, DTC B2578 or B2579 is displayed. Without a CON-
SULT-II code 30, 31, 44 or 46 is indicated on front air control as a
result of conducting self-diagnosis.
1. CHECK IN-VEHICLE SENSOR CIRCUIT
Self-diagnosis DTC B2578 or B2579 (with CONSULT-II) or code 30, 31 44 or 46 (without CONSULT-II) is
present?
YES or NO
YES >> GO TO 6.
NO >> GO TO 2.
2. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector M32 terminal 4 and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector M49.
3. Check continuity between in-vehicle sensor harness connector M32 terminal 1 and front air control harness connector M49 ter-
minal 21.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK IN-VEHICLE SENSOR
Refer to ATC-142, "
Intake Sensor Circuit" .
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> 1. Replace in-vehicle sensor. Refer to ATC-146, "
IN-VEHICLE SENSOR" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
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4 - Ground : Approx. 5V.
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1 - 21 : Continuity should exist.
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TROUBLE DIAGNOSISATC-139
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Revision: November 2009 2006 QX56
5. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between in-vehicle sensor harness connector M32 terminal 4 and front air control harness connector M50 ter-
minal 32.
4. Check continuity between in-vehicle sensor harness connector M32 terminal 4 and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> Repair harness or connector.
6. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR MOTOR AND FRONT AIR CON-
TROL (SELF-DIAGNOSIS CODES 30, 31, 44, 46 OR DTC B2578, B2579)
1. Turn ignition switch OFF.
2. Disconnect front air control connector and in-vehicle sensor con- nector.
3. Check continuity between in-vehicle sensor harness connector M32 terminal 2 and 3 and front air control harness connector
M50 terminal 44 and 43.
4. Check continuity between in-vehicle sensor harness connector M32 terminal 2 and 3 and ground.
OK or NG
OK >> 1. Replace front air control. Refer to ATC-144, "FRONT AIR CONTROL" .
2. Go to AT C - 5 6 , "
A/C System Self-diagnosis Function" and perform self-diagnosis.
NG >> Repair harness or connector. 4 - 32
: Continuity should exist.
4 - Ground Continuity should not exist.
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2 - 44: Continuity should exist.
3 - 43 : Continuity should exist.
2, 3 - Ground :Continuity should not exist.
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