NISSAN X-TRAIL 2005 Service Repair Manual

TROUBLE DIAGNOSIS
ATC-83
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SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:

Auto amp.

A/C LAN system (PBR built-in air mix door motor, mode door motor and intake door motor)

Fan control amp.

In-vehicle sensor

Ambient sensor

Sunload sensor

Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the auto amp. based on input from the PBR,
in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
The blower motor applied voltage ranges from approximately 4 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 4 to 12V), the auto amp. supplies a gate voltage to the fan control
amp. Based on this voltage, the fan control amp. controls the voltage supplied to the blower motor.
*7AT C - 11 4 , "Sunload Sensor Circuit".*8ATC-117, "Intake Sensor Circuit".*9AT C - 3 4 , "SYMPTOM TABLE".
*10AT C - 5 9 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 9.*11ATC-84, "
DIAGNOSTIC PROCE-
DURE FOR BLOWER MOTOR".*12 QR engine; (WITH EURO-OBD) EC-165, "DTC P0117, P0118 ECT SEN-
SOR" .
QR engine; (WITHOUT EURO-OBD)
EC-652, "
DTC P0117, P0118 ECT
SENSOR" .
YD engine; (WITH EURO-OBD) EC-
1093, "DTC P0117, P0118 ECT
SENSOR" .
YD engine; (WITHOUT EURO-OBD)
EC-1449, "
DTC P0117, P0118 ECT
SENSOR" .
RJIA2833E

ATC-84
TROUBLE DIAGNOSIS

Starting Fan Speed Control
Start Up from COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56°C (133°F), the blower will not
operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the
ambient and engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
56°C (133°F), and then the blower speed will increase to the objective speed.
Start Up from Usual or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the A/C switch is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
Blower Speed Compensation
Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The low speed will vary depending on the sunload. During conditions of low or no sunload, the blower
low speed is usual low speed (approx. 4V). During high sunload conditions, the auto amp. causes the blower
fan speed to increase.(Approx. 7V)
Fan Speed Control Specification
COMPONENT DESCRIPTION
Fan Control Amp.
The fan control amp. is located on the intake unit. The fan control
amp. receives a gate voltage from the auto amp. to steplessly main-
tain the blower fan motor voltage in the 4 to 12 volt range.
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning.
RJIA0522E
RJIA0523E
RHA467GA

TROUBLE DIAGNOSIS
ATC-85
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1. CHECK POWER SUPPLY FOR BLOWER MOTOR
1. Disconnect blower motor connector.
2. Turn ignition switch ON.
3. Check voltage between blower motor harness connector M65
terminal 1 (L/W) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 15A fuses [Nos. 19 and
24, located in the fuse block (J/B)]. Refer to PG-79,
"FUSE BLOCK - JUNCTION BOX (J/B)" .

If OK, check harness for open circuit. Repair or replace if necessary.

If NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
2. CHECK FAN FEED BACK CIRCUIT
1. Reconnect blower motor connector.
2. Check voltage between auto amp. harness connector M52 ter-
minal 18 (R) and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 9.
3. CHECK BLOWER MOTOR
Refer to AT C - 8 7 , "
Blower Motor" .
OK or NG
OK >> GO TO 4.
NG >> Replace blower motor.
4. CHECK POWER SUPPLY FOR FAN CONTROL AMP.
1. Turn ignition switch ON.
2. Check voltage between fan control amp. harness connector
M67 terminal 3 (R) and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.1 – Ground : Battery voltage
RJIA2860E
18 – Ground : Battery voltage
RJIA2861E
Terminals
Condition Voltage (+)
(-)
Fan control
amp. connectorTerminal No.
(wire color)
M67 3 (R) Ground Fan speed: 1st Approx. 8V
RJIA2862E

ATC-86
TROUBLE DIAGNOSIS

5. CHECK GROUND CIRCUIT FOR FAN CONTROL AMP.
1. Turn ignition switch OFF.
2. Disconnect fan control amp. connector.
3. Check continuity between fan control amp. harness connector
M67 terminal 1 (B) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK FOR AUTO AMP. OUTPUT SIGNAL
1. Reconnect fan control amp. connector.
2. Turn ignition switch ON.
3. Check voltage between fan control amp. harness connector
M67 terminal 2 (L/Y) and ground.
OK or NG
OK >> GO TO 9.
NG >>

If the voltage is less than 2.5V: GO TO 7.

If the voltage is more than 9.0V: GO TO 8.
7. CHECK CIRCUIT CONTINUITY BETWEEN AUTO AMP. AND FAN CONTROL AMP.
1. Turn ignition switch OFF.
2. Disconnect auto amp. connector and fan control amp. connec-
tor.
3. Check continuity between auto amp. harness connector M52
terminal 17 (L/Y) and fan control amp. harness connector M67
terminal 2 (L/Y).
OK or NG
OK >> Replace fan control amp.
NG >> Repair harness or connector.1 – Ground : Continuity should exist.
RJIA2863E
Terminals
Condition Voltage (+)
(-) Fan control
amp. connec-
torTerminal No.
(wire color)
M67 2 (L/Y) GroundFan speed: 1st
- 24thApprox. 2.5 -
3.5V
Fan
speed:25thApprox. 9.0V
RJIA2864E
17 – 2 : Continuity should exist.
RJIA2865E

TROUBLE DIAGNOSIS
ATC-87
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8. CHECK FAN CONTROL AMP.
1. Turn ignition switch OFF.
2. Disconnect fan control amp. connector.
3. Check continuity between fan control amp. connector M67 ter-
minal 2 and 1.
OK or NG
OK >> GO TO 9.
NG >> Replace fan control amp.
9. CHECK CIRCUIT CONTINUITY BETWEEN AUTO AMP. AND FAN CONTROL AMP.
1. Disconnect auto amp. connector.
2. Check continuity between auto amp. harness connector M52
terminal 18 (R) and fan control amp. harness connector M67 ter-
minal 3 (R).
OK or NG
OK >> Replace auto amp.
NG >> Repair harness or connector.
COMPONENT INSPECTION
Blower Motor
Confirm smooth rotation of blower motor.

Ensure that there are no foreign particles inside intake unit.2 – 1 : Continuity should exist.
SJIA0476E
18 – 3 : Continuity should exist.
RJIA2867E
RJIA0532E

ATC-88
TROUBLE DIAGNOSIS

Magnet Clutch CircuitEJS004YO
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
*1AT C - 6 5 , "Operational Check".*2ATC-59, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 1.*3ATC-59, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 5 to
7.
*4ATC-109, "
Ambient Sensor Circuit".*5ATC-117, "Intake Sensor Circuit".*6ATC-34, "SYMPTOM TABLE".
*7AT C - 5 9 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 9.*8ATC-89, "
DIAGNOSTIC PROCE-
DURE FOR MAGNET CLUTCH".*9ATC-102, "
TROUBLE DIAGNOSIS
FOR UNUSUAL PRESSURE".
RJIA3103E

TROUBLE DIAGNOSIS
ATC-89
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SYSTEM DESCRIPTION
Auto amp. controls compressor operation by ambient temperature, intake air temperature (with diesel engine)
and signal from ECM.
Low Temperature Protection Control (With Gasoline Engine)
Auto amp. will turn compressor ON or OFF as determined by a sig-
nal detected by ambient sensor.
When ambient temperatures are higher than −2°C (28°F), compres-
sor turns ON. Compressor turns OFF when ambient temperatures
are lower than −5°C (23°F).
Evaporator Freeze Protection Control (With Diesel Engine)
Auto amp. will turn compressor ON or OFF as determined by a sig-
nal detected by intake sensor.
When intake air temperatures are higher than 4°C (39°F), compres-
sor turns ON. Compressor turns OFF when intake temperatures are
lower than 2.5°C (37°F).
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
RHA094GB
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RJIA2835E

ATC-90
TROUBLE DIAGNOSIS

1. CHECK POWER SUPPLY FOR COMPRESSOR
1. Disconnect compressor connector.
2. Start the engine.
3. Turn fan control dial to AUTO position.
4. Press A/C switch.
5. Check voltage between compressor harness connector E34 ter-
minal 1 (L/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> 1. Repair harness or connector.
2. Go to self-diagnosis procedure AT C - 5 9 , "
FUNCTION
CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-4. Confirm that magnet clutch opera-
tion is usual.
NG >> 1. Replace magnet clutch. Refer to ATC-146, "
Removal
and Installation of Compressor Clutch" .
2. Go to self-diagnosis procedure AT C - 5 9 , "
FUNCTION
CONFIRMATION PROCEDURE" and perform self-diagnosis STEP-4. Confirm that magnet
clutch operation is usual.
3. CHECK CIRCUIT CONTINUITY BETWEEN A/C RELAY AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect A/C relay connector.
3. Check continuity between A/C relay harness connector E5 ter-
minal 5 (L/R) and compressor harness connector E34 terminal 1
(L/R).
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.1 – Ground : Battery voltage
RJIA2869E
RJIA2005E
5 – 1 : Continuity should exist.
RJIA2870E

TROUBLE DIAGNOSIS
ATC-91
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4. CHECK POWER SUPPLY FOR A/C RELAY
1. Turn ignition switch ON.
2. Check voltage between A/C relay harness connector E5 termi-
nal 1 (BR/Y), 3 (BR/Y) and ground.
OK or NG
OK >> GO TO 5.
NG >> Check power supply circuit and 10A fuse [No. 15
located in the fuse block (J/B)]. Refer to PG-79, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .

If OK, check harness for open circuit. Repair or replace if necessary.

If NG, replace fuse and check harness for short circuit. Repair or replace if necessary.
5. CHECK A/C RELAY AFTER DISCONNECTING IT
Refer to AT C - 9 4 , "
A/C Relay" .
OK or NG
OK >> GO TO 6.
NG >> 1. Replace A/C relay.
2. Go to self-diagnosis procedure AT C - 5 9 , "
FUNCTION CONFIRMATION PROCEDURE" and
perform self-diagnosis STEP-4. Confirm that magnet clutch operation is usual.
6. CHECK COIL SIDE CIRCUIT OF A/C RELAY
1. Turn ignition switch OFF.
2. Reconnect A/C relay connector.
3. Start the engine.
4. Check voltage between ECM harness connector F43 terminal
105 (BR/W) or 19 (L) and ground.
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK AMBIENT SENSOR
Refer to ATC-109, "
Ambient Sensor Circuit" .
OK or NG
OK >>
With gasoline engine: GO TO 8.

With diesel engine: GO TO 14.
NG >> Repair or replace the malfunctioning part(s).
8. CHECK REFRIGERANT PRESSURE SENSOR (QR ENGINE)
Refer to AT C - 9 4 , "
Refrigerant Pressure Sensor (With Gasoline Engine)" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace the malfunctioning part(s).1 – Ground : Battery voltage
3 – Ground : Battery voltage
RJIA2871E
105 – Ground (Gasoline engine) : Battery voltage
19 – Ground (Diesel engine) : Battery voltage
RJIA2836E

ATC-92
TROUBLE DIAGNOSIS

9. CHECK VOLTAGE FOR AUTO AMP. (COMPRESSOR ON SIGNAL)
1. Turn ignition switch ON.
2. Check voltage between auto amp. harness connector M52 ter-
minal 4 (L/R) and ground.
OK or NG
OK >> GO TO 10.
NG >>

If the voltage is approx. 5V when the A/C switch is ON: Replace the auto amp.

If the voltage is approx. 0V when the A/C switch is OFF: GO TO 12.
10. CHECK VOLTAGE FOR AUTO AMP. (FAN ON SIGNAL)
Check voltage between auto amp. harness connector M52 terminal
19 (LG/B) and ground.
OK or NG
OK >> Replace auto amp.
NG >>

If the voltage is approx. 5V when the blower motor is ON: Replace the auto amp.

If the voltage is approx. 0V when the blower motor is OFF: GO TO 11.
11 . CHECK CIRCUIT CONTINUITY BETWEEN ECM AND AUTO AMP.
1. Turn ignition switch OFF.
2. Disconnect ECM connector and auto amp. connector.
3. Check continuity between ECM harness connector F43 terminal
96 (LG/B) and auto amp. harness connector M52 terminal 19
(LG/B).
OK or NG
OK >> INSPECTION END
NG >> Repair harness or connector.
Te r m i n a l s
Condition Voltage (+)
(-)
Auto amp.
connectorTerminal No.
(wire color)
M52 4 (L/R) GroundA/C SW: ON
(Blower motor
operates.)Approx. 0V
A/C SW: OFF Approx. 5V
RJIA2873E
Terminals
Condition Voltage (+)
(-)
Auto amp.
connectorTerminal No.
(wire color)
M52 19 (LG/B) GroundBlower fan: ON
(Blower motor
operates.)Approx. 0V
Fan contorol dial:
OFFApprox. 5V
RJIA2874E
96 – 19 : Continuity should exist.
RJIA2837E