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ATC-36
TROUBLE DIAGNOSIS
Component Parts and Harness Connector LocationBJS000FT
ENGINE COMPARTMENT
RJIA2730E
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ATC-46
TROUBLE DIAGNOSIS
Self-diagnosis FunctionBJS000FX
DESCRIPTION
The self-diagnosis system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-
cable sections (items) for details. Shifting from usual control to the self-diagnosis system is accomplished by
starting the engine (turning the ignition switch ON) and pressing A/C switch for at least 5 seconds. The A/C
switch must be pressed within 10 seconds after starting the engine (ignition switch is turned ON). This system
will be canceled by either pressing AUTO switch or turning the ignition switch OFF. Shifting to the next step is
accomplished by means of pressing temperature control switch (driver side), as required.
Additionally sifting from STEP-5 to AUXILIARY MECHANISM is accomplished by means of pressing (fan)
control switch (UP).
SJIA1670E
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TROUBLE DIAGNOSIS
ATC-47
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FUNCTION CONFIRMATION PROCEDURE
1. SET IN SELF-DIAGNOSIS MODE
1. Turn ignition switch ON.
2. Set in self-diagnosis mode as follows. Within 10 seconds after starting engine (ignition switch is turned
ON.), press A/C switch for at least 5 seconds.
CAUTION:
Press A/C switch after indicating LED of intake switch.
If battery voltage drops below 12 V during diagnosis STEP-3, door motor speed becomes slower
and as a result, the system may generate an error even when operation is normal. To avoid this,
start engine before performing this diagnosis.
Former STEP-1 (LEDs and display screen are checked) does not exist in this self-diagnosis func-
tion.
>> GO TO 2.
2. STEP-2: SENSOR CIRCUITS ARE CHECKED FOR OPEN OR SHORT CIRCUIT
Does code No. 20 appear on the display?
YES >> GO TO 3.
NO >> GO TO 13.
3. CHECK TO ADVANCE SELF-DIAGNOSIS STEP-3
Press temperature control switch (UP, driver side).
Advance to self
-diagnosis STEP-3?
YES >> GO TO 4.
NO >> Replace A/C and AV switch. (Temperature control switch is malfunctioning.)
4. CHECK TO RETURN SELF-DIAGNOSIS STEP-2
Press temperature control switch (DOWN, driver side).
Return to self
-diagnosis STEP-2?
YES >> GO TO 5.
NO >> Malfunctioning A/C and AV switch or unified meter and A/C amp. Refer to AT C - 9 4 , "
Self-diagno-
sis" .
5. STEP-3: MODE DOOR AND INTAKE DOOR POSITIONS ARE CHECKED
Press temperature control switch (UP, driver side).
Does code No. 30 appear on the display?
YES >> GO TO 6.
NO >> GO TO 14.
RHA970DB
RHA869DD
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ATC-54
TROUBLE DIAGNOSIS
Operational CheckBJS000FY
The purpose of the operational check is to confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Press temperature control switch (UP, driver side) until 32°C is displayed.
2. Press fan control switch (DOWN) at least 2 seconds.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press fan control switch (DOWN) at least 2 seconds.
If NG, go to trouble diagnosis procedure for AT C - 9 5 , "
Memory Function" .
If OK, continue the check.
CHECKING BLOWER
1. Press fan control switch (UP). Blower should operate on low speed. The fan symbol should have one
blade lit.
2. Press fan control switch (UP) again, and continue checking blower speed and fan symbol until all speeds
are checked.
3. Leave blower on max. speed.
If NG, go to trouble diagnosis procedure for AT C - 7 2 , "
Blower Motor Circuit" .
If OK, continue the check.
CHECKING DISCHARGE AIR
1. Press MODE switch and DEF switch.
2. Each position indicator should change shape.
3. Confirm that discharge air comes out according to the air distri-
bution table. Refer to AT C - 3 1 , "
Discharge Air Flow" .
If NG, go to trouble diagnosis procedure for AT C - 6 3 , "
Mode Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the DEF is
selected.
CHECKING INTAKE AIR
1. Press intake switch. Recirculation indicator should illuminate.
2. Press intake switch again. Fresh indicator should illuminate.
3. Listen for intake door position change (Slight change of blower sound can be heard.).
If NG, go to trouble diagnosis procedure for AT C - 6 9 , "
Intake Door Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at
FRESH when the DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature control switch (DOWN, driver side) until 18°C is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 8 4 , "
Insufficient Cooling" .
If OK, continue the check.Conditions : Engine running at normal operating temperature
SJIA1002E
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ATC-72
TROUBLE DIAGNOSIS
Blower Motor CircuitBJS000G5
SYMPTOM: Blower motor operation is malfunctioning.
INSPECTION FLOW
*1AT C - 5 4 , "Operational Check"*2ATC-105, "Intake Sensor Circuit"*3AT C - 4 7 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2.
*4AT C - 4 7 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 6.*5ATC-47, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.*6AT C - 7 4 , "
DIAGNOSIS PROCE-
DURE FOR BLOWER MOTOR"
*7AT C - 3 5 , "SYMPTOM TABLE"*8ATC-96, "Ambient Sensor Circuit"*9AT C - 9 9 , "In-vehicle Sensor Circuit"
*10ATC-102, "Sunload Sensor Circuit"*11EC-131, "DTC P0117, P0118 ECT
SENSOR" (QR engine) or EC-474,
"DTC P0117, P0118 ECT SEN-
SOR" (VQ engine)
RJIA3261E
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TROUBLE DIAGNOSIS
ATC-73
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SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:
Unified meter and A/C amp.
A/C LAN system (PBR built-in mode door motor, air mix door motor and intake 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 control signal is calculated by the unified meter and A/C amp.
based on the input from the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
The blower motor applied voltage ranges from approximately 3.5 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 3.5 to 12 V), unified meter and A/C amp. supplies a gate voltage to
the fan control amp. Based on this voltage, fan control amp. controls 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.
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 AUTO switch is pressed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
RJIA3262E
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TROUBLE DIAGNOSIS
ATC-81
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7. CHECK VOLTAGE FOR UNIFIED METER AND A/C AMP. (COMPRESSOR ON SIGNAL)
1. Reconnect BCM connector and unified meter and A/C amp.
connector.
2. Turn ignition switch ON.
3. Check voltage between unified meter and A/C amp. harness
connector M45 terminal 42 and ground.
OK or NG
OK >> GO TO 8.
NG-1 >> If the voltage is approx. 5 V when A/C switch is ON: Replace unified meter and A/C amp.
NG-2 >> If the voltage is approx. 0 V when A/C switch is OFF: Replace BCM.
8. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start the engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-90,
"CONSULT-II Reference Value in Data Monitor Mode" (QR
engine) or EC-434, "
CONSULT-II Reference Value in Data Mon-
itor Mode" (VQ engine).
WITHOUT CONSULT-II
1. Start the engine.
2. Check voltage between ECM harness connector F101 terminal
70 and ground.
OK or NG
OK >>WITH CONSULT-II: GO TO 9.
WITHOUT CONSULT-II: GO TO 10.
NG >> Refer to EC-339, "
REFRIGERANT PRESSURE SENSOR" (QR engine) or EC-748, "REFRIGER-
ANT PRESSURE SENSOR" (VQ engine).
Te r m i n a l s
Condition Voltage (+)
(-) Unified meter
and A/C amp.
connectorTerminal
No.
M45 42 GroundA/C switch: ON
(Blower motor oper-
ates.)Approx. 0 V
OFF switch: ON (A/C
System: OFF)Approx. 5 V
RJIA2007E
Terminals
Condition Voltage (+)
(-)
ECM con-
nectorTerminal No.
F10169 (QR engine)
GroundA/C switch: ON
(Blower motor
operates.)Approx. 1.0 - 4.0 V
70 (VQ engine)
SJIA1723E
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TROUBLE DIAGNOSIS
ATC-83
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12. CHECK CAN COMMUNICATION
Check CAN communication. Refer to BCS-14, "
CAN Communication Inspection Using CONSULT-II (Self-
Diagnosis)" .
BCM – ECM
ECM – IPDM E/R
ECM – Unified meter and A/C amp.
OK or NG
OK >> Replace ECM.
NG >> Repair or replace malfunctioning part(s).
COMPONENT INSPECTION
Refrigerant Pressure Sensor
The refrigerant pressure sensor is attached to the condenser.
Make sure that the A/C refrigerant pressure and the sensor output
voltage are as shown in the A/C operating condition figure. Refer to
EC-339, "
REFRIGERANT PRESSURE SENSOR" (QR engine) or
EC-748, "
REFRIGERANT PRESSURE SENSOR" (VQ engine).
RJIA1795E
RJIA2954E
