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ATC-46
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Refer to the following chart and check discharge air flow, air temper-
ature, blower motor duty ratio and compressor operation.
Checks must be made visually, by listening the sound, or by touching air outlets with hand, etc. for improper
operation.
*1: FOOT position during automatic control. Refer to "AUXILIARY MECHANISM: FOOT POSITION SETTING
TRIMMER".
OK or NG
OK >> GO TO 8.
NG >> Air outlet does not change.
Go to Mode Door Motor Circuit. Refer to ATC-57, "
Mode Door Motor Circuit".
Intake door does not change. Go to Intake Door Motor Circuit. Refer to ATC-62, "
Intake Door Motor Circuit".
Discharge air temperature does not change. Go to Air Mix Door Motor Circuit. Refer to ATC-59, "
Air Mix Door Motor Circuit".
Blower motor operation is malfunctioning.
Go to Blower Motor Circuit. Refer to ATC-64, "
Blower Motor Circuit".
Magnet clutch does not engage. Go to Magnet Clutch Circuit. Refer to ATC-69, "
Magnet Clutch Circuit".
8.STEP-5: TEMPERATURE OF EACH SENSOR IS CHECKED
1. Press temperature control (UP) switch (driver side).
2. Code No. 51 appears on the display.
>> GO TO 9.
9.CHECK AMBIENT SENSOR
Press (DEF) switch one time. Temperature detected by ambient
sensor is indicated on the display.
NOTE:
If the temperature indicated on the display greatly differs from the
actual temperature, check sensor circuit first, and then check sensor.
OK or NG
OK >> GO TO 10.
NG >> Go to Ambient Sensor Circuit. Refer to ATC-86, "
Ambi-
ent Sensor Circuit".
SJIA0302E
Code No. 414243444546
Mode door position VENT B/L 1 B/L 2
FOOT
*1D/F DEF
Intake door position REC REC 20% FRE FRE FRE FRE
Air mix door position FULL COLD FULL COLD FULL HOT FULL HOT FULL HOT FULL HOT
Blower motor duty ratio 37% 91% 65% 65% 65% 91%
Compressor ON ON OFF OFF ON ON
Electronic control valve
(ECV) duty ratio 100% 100% 0% 0% 50% 100%
PJIA0151E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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TROUBLE DIAGNOSISATC-51
< SERVICE INFORMATION >
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1. Press fan (UP:+) switch. Blower should operate on low speed. The fan symbol should have one blade lit.
2. Press fan (UP:+) switch again, and continue che cking blower speed and fan symbol until all speeds are
checked.
3. Leave blower on max. speed.
If NG, go to trouble diagnosis procedure for ATC-64, "
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 ATC-29, "
Discharge Air Flow".
If NG, go to trouble diagnosis procedure for ATC-57, "
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 FRE when the D/F or 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. (S light change of blower sound can be heard.)
If NG, go to trouble diagnosis procedure for ATC-62, "
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 FRE
when the D/F or DEF is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature control (DOWN) switch (driver side) until 18 °C (60 °F) is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-75, "
Insufficient Cooling".
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature control (UP) switch (driver side) until 32 °C (90 °F) is displayed.
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-82, "
Insufficient Heating".
If OK, continue the check.
CHECKING A/C SWITCH
1. Press AUTO switch and A/C switch.
2. A/C switch indicator will turn ON. Confirm that the compressor clutch engages (sound or visual inspection).
If NG, go to trouble diagnosis procedure for ATC-69, "
Magnet Clutch Circuit".
If OK, continue the check.
CHECKING AUTO MODE
1. Press AUTO switch and A/C switch.
2. Display should indicate AUTO. Confirm that discharge air and blower speed will depend on ambient, in-vehicle, and set temperatures.
If NG, go to trouble diagnosis procedure for ATC-52, "
Power Supply and Ground Circuit for Auto Amp", then if
necessary, trouble diagnosis procedure for ATC-69, "
Magnet Clutch Circuit".
SJIA0302E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-69
< SERVICE INFORMATION >
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Confirm smooth rotation of the blower motor.
Ensure that there are no foreign particles inside the blower unit.
Magnet Clutch CircuitINFOID:0000000001328190
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
RJIA0905E
*1 AT C - 9 4 , "Intake Sensor Circuit"*2AT C - 8 6 , "Ambient Sensor Circuit"*3 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13.
SJIA1590E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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Page 475 of 3924

ATC-70
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature
and signal from ECM.
Low Temperature Protection Control
Unified meter and A/C amp. will turn the compressor ON or OFF as determined by a signal detected by ambi-
ent sensor and intake sensor.
When ambient temperature is higher than −2 °C (28 °F), the compres-
sor turns ON. The compressor turns OFF when ambient temperature
is lower than −5 °C (23 °F).
When intake air temperature is higher than 1 °C (34 °F), the compres-
sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than −5 °C (23 °F).
DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
1.CHECK AMBIENT SENSOR AND INTAKE SENSOR CIRCUIT
Check ambient sensor and intake sensor. Refer to ATC-43, "
Self-Diagnosis Function", see No. 9 and 11.
*4 "DIAGNOSIS PROCEDURE FOR
MAGNET CLUTCH" *5
AT C - 7 5 , "Insufficient Cooling"*6AT C - 5 0 , "Operational Check"
*7AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *8
AT C - 3 2 , "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
RHA094GB
SJIA0267E
SJIA1608E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-71
< SERVICE INFORMATION >
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OK or NG
OK >> GO TO 2.
NG >> Malfunctioning ambient sensor: Refer to ATC-86, "
Ambient Sensor Circuit".
Malfunctioning intake sensor: Refer to ATC-94, "
Intake Sensor Circuit".
2.PERFORM IPDM E/R AUTO ACTIVE TEST
Perform “IPDM E/R auto active test”. Refer to PG-20, "
Auto Active Test".
Does the magnet clutch operate?
YES >> WITH CONSULT-III: GO TO 5 WITHOUT CONSULT-III: GO TO 6.
NO >> Check 10A fuse (No. 79, located in IPDM E/R). Refer to PG-23, "
IPDM E/R Terminal Arrange-
ment", and GO TO 3.
3.CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector and compressor connector.
3. Check continuity between IPDM E/R harness connector E8 ter- minal 33 and compressor harness connector F2 terminal 1.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK MAGNET CLUTCH CIRCUIT
Check for operation sound when applying battery voltage direct cur-
rent to terminal.
OK or NG
OK >> 1. Replace IPDM E/R. 2. Go to self-diagnosis procedure ATC-43, "
Self-Diag-
nosis Function" and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
NG >> 1. Replace magnet clutch.
2. Go to self-diagnosis procedure ATC-43, "
Self-Diag-
nosis Function" and perform self-diagnosis STEP-4.
Confirm that magnet clutch operation normal.
5.CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal in “Data monitor”. Refer to ATC-32, "
CONSULT-III Function".
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK CIRCUIT CONTINUITY BETWEEN BC M AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect BCM connector and unified meter and A/C amp. connector.
33 – 1 : Continui ty should exist.
RJIA2004E
RJIA2005E
A/C SW ON : AIR COND SW ON
A/C SW OFF : AIR COND SW OFF
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
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TROUBLE DIAGNOSISATC-75
< SERVICE INFORMATION >
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Insufficient CoolingINFOID:0000000001328191
SYMPTOM: Insufficient cooling
INSPECTION FLOW
*1 AT C - 4 3 , "Self-Diagnosis Function",
see No. 4 to 6. *2
AT C - 5 9 , "Air Mix Door Motor Circuit"*3 "Test Reading"
*4 AT C - 4 3 , "
Self-Diagnosis Function"*5 AT C - 4 3 , "Self-Diagnosis Function",
see No. 13. *6
AT C - 5 4 , "LAN System Circuit"
*7AT C - 6 4 , "Blower Motor Circuit"*8 AT C - 6 9 , "Magnet Clutch Circuit"*9 "PERFORMANCE TEST DIAGNO-
SIS"
SJIA1592E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-77
< SERVICE INFORMATION >
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PERFORMANCE CHART
Test Condition
Testing must be performed as follows:
*1 ATC-125, "Removal and Installation
of Compressor Clutch"
*2AT C - 6 4 , "Blower Motor Circuit"*3 EM-14, "Checking Drive Belts"
(VQ35DE) or EM-170, "
Checking
Drive Belts" (VK45DE)
SJIA1642E
Vehicle condition Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door windows Open
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ATC-84
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Self-Diagnosis
INFOID:0000000001328194
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1 ATC-125, "Removal and Installation
of Compressor Clutch"
*2ATC-125, "Removal and Installation
of Compressor Clutch"
*3AT C - 2 2 , "Maintenance of Lubricant
Quantity in Compressor"
*4AT C - 5 0 , "Operational Check"*5EM-14, "Checking Drive Belts"
(VQ35DE) or EM-170, "
Checking
Drive Belts" (VK45DE)
RJIA3108E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C