Page 2049 of 3189
TROUBLE DIAGNOSIS
ATC-69
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Blower Motor CircuitEJS001ZO
SYMPTOM:
●Blower motor operation is malfunctioning.
●Blower motor operation is malfunctioning under out of starting fan speed control.
INSPECTION FLOW
RJIA1696E
Page 2050 of 3189

ATC-70
TROUBLE DIAGNOSIS
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 automatic amplifier 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 automatic amplifier supplies a gate voltage to the fan
control amplifier. Based on this voltage, the fan control amplifier controls the voltage supplied to the blower
motor.
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.
*1AT C - 4 2 , "Self-diagnosis Function"*2AT C - 4 2 , "Self-diagnosis Function",
see No.14.*3AT C - 6 9 , "Blower Motor Circuit"
*4AT C - 5 1 , "Operational Check"*5AT C - 2 9 , "SYMPTOM TABLE"*6 QG engine (With EURO–OBD): EC-
144, "DTC P0117, P0118 ECT SEN-
SOR"
QG engine (Without EURO–OBD):
EC-501, "
DTC P0117, P0118 ECT
SENSOR"
YD engine: EC-84, "DTC 0115
COOLANT TEMP SEN"
RJIA0785E
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TROUBLE DIAGNOSIS
ATC-71
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AT C
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), at which time 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 button 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 Amplifier
The fan control amplifier is located on the heater & cooling unit. The
fan control amp. receives a gate voltage from the auto amp. to step-
lessly maintain the blower fan motor voltage in the 4 to 12 volt range.
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning under starting
fan speed control.
RJIA0522E
RHA625H
RJIA0786E
Page 2052 of 3189

ATC-72
TROUBLE DIAGNOSIS
1. CHECK POWER SUPPLY FOR BLOWER MOTOR
Disconnect blower motor harness connector.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 15A fuses (Nos. 14 and
16, located in the fuse block). Refer to EL-11, "POWER
SUPPLY ROUTING".
●If OK, check for open circuit in wiring harness. Repair or replace as necessary.
●If NG, replace fuse and check wiring harness for short circuit. Repair or replace as necessary.
2. CHECK FAN FEED BACK CIRCUIT
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK BLOWER MOTOR
Refer to COMPONENT INSPECTION.
OK or NG
OK >> GO TO 4.
NG >> Replace blower motor.
4. CHECK POWER SUPPLY FOR FAN CONTROL AMP.
1. Reconnect blower motor connector.
2. Disconnect fan control amp. harness connector.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
Terminal
Vo l ta g e (+)
(-)
Blower motor con-
nectorTerminal No.
(Wire color)
M59 1 (L/W) Ground Approx. 12V
RJIA0524E
Te r m i n a l
Condition Voltage (+)
(-)
Auto amp.
connectorTerminal No.
(Wire color)
M205 34 (L/B) Ground Fan speed: 1st Approx. 8V
RJIA0787E
Te r m i n a l
Voltag e (+)
(-)
Fan control amp.
connectorTerminal No.
(Wire color)
M190 3 (L/B) Ground Approx. 12V
RJIA0526E
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TROUBLE DIAGNOSIS
ATC-73
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5.CHECK GROUND CIRCUIT FOR FAN CONTROL AMP.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6.CHECK FOR AUTO AMP. OUTPUT
Reconnect the fan control amp. harness connector.
OK or NG
OK >> GO TO 9.
NG >>
●If the voltage is less than 2.5V: GO TO 8.
●If the voltage is more than 9.0V: GO TO 7.
7.CHECK CIRCUIT CONTINUITY BETWEEN AUTO AMP. AND FAN CONTROL AMP.
Disconnect the auto amp. harness connector and fan control amp.
harness connector.
OK or NG
OK >> Replace fan control amp.
NG >> Repair harness or connector.
8.CHECK FAN CONTROL AMP.
Disconnect the fan control amp. harness connector.
OK or NG
OK >> GO TO 9.
NG >> Replace fan control amp.
Te r m i n a l
Continuity (+)
(-)
Fan control amp.
connectorTerminal No.
(Wire color)
M190 1 (B) Ground Yes
RJIA0527E
Terminal
Condition Voltage (+)
(-) Fan control
amp. connec-
torTe r m i n a l N o .
(Wire color)
M190 2 (L/Y) GroundFan speed: 1 - 4 Approx. 2.5 - 3.5
Fan speed: 5 Approx. 9.0
RJIA0528E
Terminal
Continuity Auto amp. Fan control amp.
ConnectorTerminal No.
(Wire color)Connector Terminal No.
(Wire color)
M205 35 (L/Y) M190 2 (L/Y) Yes
RJIA0788E
Terminal
Continuity (+) (-)
Fan control
amp. connectorTe r m i n a l N o .
(Wire color)Fan control
amp. connectorTerminal No.
(Wire color)
M190 2 M190 1 Yes
RJIA0530E
Page 2054 of 3189
ATC-74
TROUBLE DIAGNOSIS
9. CHECK CIRCUIT CONTINUITY BETWEEN AUTO AMP. AND FAN CONTROL AMP.
OK or NG
OK >> Replace auto amp.
NG >> Repair harness or connector.
COMPONENT INSPECTION
Blower Motor
Confirm smooth rotation of the blower motor.
●Ensure that there are no foreign particles inside the intake unit.
Te r m i n a l
Continuity (+) (-)
Auto amp.
connectorTerminal No.
(Wire color)Fan control
amp. Con-
nectorTe r m i n a l N o .
(Wire color)
M205 34 (L/B) M190 3 (L/B) Yes
RJIA0789E
RJIA0790E
Page 2055 of 3189
TROUBLE DIAGNOSIS
ATC-75
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AT C
Magnet Clutch CircuitEJS001ZP
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
*1ATC-42, "Self-diagnosis Function",
see No.1.*2ATC-100, "Ambient Sensor Circuit"*3ATC-102, "In-vehicle Sensor Circuit"
*4ATC-105, "Sunload Sensor Circuit"*5AT C - 6 3 , "Air Mix Door Motor Circuit"*6ATC-42, "Self-diagnosis Function",
see No. 14.
*7ATC-75, "
Magnet Clutch Circuit"*8AT C - 9 2 , "TROUBLE DIAGNOSES
FOR UNUSUAL PRESSURE"
*9ATC-51, "Operational Check"
*10ATC-42, "Self-diagnosis Function"
see No.5 or 7.*11AT C - 2 9 , "
SYMPTOM TABLE"*12ATC-108, "Intake Sensor Circuit"
RJIA1697E
Page 2056 of 3189
ATC-76
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Auto amplifier controls compressor operation by ambient temperature and signal from ECM.
Low Temperature Protection Control
Auto amplifier will turn the compressor ON or OFF as determined by
a signal detected by ambient sensor.
When ambient temperatures are greater than −2°C (28°F), the com-
pressor turns ON. The compressor turns OFF when ambient temper-
atures are less than −5°C (23°F).
DIAGNOSTIC PROCEDURE FOR MAGNET CLUTCH (WITH CAN SYSTEM)
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
RHA094GB
RJIA1698E