Page 457 of 3924

ATC-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
If all operational checks are OK (symptom cannot be duplicated), go to Incident Simulation Tests in GI-25,
"How to Perform Efficient Diagnosis for an Electrical Incident" and perform tests as outlined to simulate driving
conditions environment. If symptom appears, refer to ATC-32, "
How to Perform Trouble Diagnosis for Quick
and Accurate Repair" and perform applicable trouble diagnosis procedures.
Power Supply and Ground Circuit for Auto AmpINFOID:0000000001328183
SYMPTOM: A/C system does not activate.
INSPECTION FLOW
COMPONENT DESCRIPTION
Unified Meter and A/C Amp. (Automatic Amplifier)
The unified meter and A/C amp. has a built-in microcomputer which
processes information sent from various sensors needed for air con-
ditioner operation. The air mix door motor, mode door motor, intake
door motor, blower motor and compressor are then controlled.
When the various switches and temperature control switch are oper-
ated, data is input to the unified meter and A/C amp. from the display
control unit using CAN communication.
Self-diagnosis functions are also built into unified meter and A/C
amp. to provide quick check of malfunctions in the auto air condi-
tioner system.
Potentio Temperature Control (PTC)
*1 "DIAGNOSIS PROCEDURE FOR A/
C SYSTEM" *2
AT C - 5 0 , "Operational Check"*3AV- 7 9 , "Unable to Operate System
with A/C and AV Switch" (Without
navigation system) or AV- 1 2 7 , "
Un-
able to Operate System with A/C and
AV S w i t c h" (With navigation system)
SJIA1582E
SJIA1566E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-53
< SERVICE INFORMATION >
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The PTC is built into the A/C and AV switch. It can be set at an inter-
val of 0.5 °C (1.0 °F) in the 18 °C (60 °F) to 32 °C (90 °F) temperature
range by pressing temperature cont rol switch. The set temperature
is displayed.
DIAGNOSIS PROCEDURE FOR A/C SYSTEM
SYMPTOM: A/C system does not activate.
1.CHECK POWER SUPPLY CIRCUIT FO R UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
2. Check voltage between unified meter and A/C amp. harness connector M56 terminals 21, 22 and 35, unified meter and A/C
amp. harness connector M57 terminal 46 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check 10A and 15A fuses [Nos. 6, 10, 11, 12 and 19, located in the fuse block (J/B)]. Refer to
PG-77
.
If fuses are OK, check harness for open circuit. Repair or replace if necessary.
If fuses are NG, check harness fo r short circuit and replace fuse.
2.CHECK GROUND CIRCUIT FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
SJIA1583E
RJIA1983E
Terminals Ignition switch position
(+)
(− )OFFACC ON
Unified
meter and A/C amp.
connector Te r m i n a l N o .
M56 21
GroundBattery volt-
age Battery
voltage Battery
voltage
M56 22 Approx. 0 V Approx. 0 V Battery
voltage
M56 35 Approx. 0 V Battery
voltage Battery
voltage
M57 46 Approx. 0 V Battery
voltage Battery
voltage
RJIA1984E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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ATC-54
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
2. Check continuity between unified meter and A/C amp. harnessconnector M56 terminal 29, 30 and ground.
OK or NG
OK >> Replace unified meter and A/C amp.
NG >> Repair harness or connector.
LAN System CircuitINFOID:0000000001328184
SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT
1.CHECK POWER SUPPLY FOR UNI FIED METER AND A/C AMP.
1. Turn ignition switch ON.
2. Check voltage between unified meter and A/C amp. harness connector M57 terminal 54 and ground.
OK or NG
OK >> GO TO 2.
NG >> Replace unified meter and A/C amp.
2.CHECK SIGNAL FOR UNIFIED METER AND A/C AMP. 29, 30 – Ground : Continuity should exist.
RJIA1985E
RJIA1775E
54 – Ground : Battery voltage
RJIA1986E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-55
< SERVICE INFORMATION >
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Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M57 terminal 43 and ground using an oscilloscope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
3.CHECK POWER SUPPLY FOR EACH DOOR MOTOR
Check voltage between each door motor harness connector terminal
1 and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK SIGNAL FOR EACH DOOR MOTOR
Confirm A/C LAN signal between each door motor harness connec-
tor terminal 3 and ground using an oscilloscope.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5.CHECK MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect each door motor connector.
Te r m i n a l s
Vo l ta g e
(+)
(− )
Unified meter and A/
C amp. connector Te r m i n a l N o .
M57 43 Ground
RJIA1987E
SJIA1453J
1 – Ground : Battery voltage
RJIA1988E
Door motor Te r m i n a l s
Vol tag e
(+)
(− )
Con-
nector Te r m i n a l
No.
Mode M258 3
Ground
Air mix
(Driver
side)
M252 3
Air mix
(Passen-
ger side) M257 3
Intake M253 3
RJIA1989E
SJIA1453J
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-67
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COMPONENT DESCRIPTION
Brush-Less Motor
The blower motor utilizes a brush-less motor with a rotating magnet.
Quietness is improved over previous motors where the brush was
the point of contact and the coil rotated.
DIAGNOSIS PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning.
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 M78 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)]. Refer to PG-
77.
If fuses are OK, check harness for open circuit. Repair or replace if necessary.
If fuses are NG, check harness fo r short circuit and replace fuse.
2.CHECK BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between blower motor harness connector M78 terminal 3 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
ZHA152H
SJIA0266E
1 – Ground : Battery voltage
RJIA1997E
3 – Ground : Continuity should exist.
RJIA1998E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-81
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DIAGNOSIS PROCEDURE FOR INSUFFICIENT COOLING
SYMPTOM: Insufficient cooling
1.CHECK POWER SUPPLY FOR ECV (ELECTRONIC CONTROL VALVE)
1. Disconnect compressor (ECV) connector.
2. Turn ignition switch ON.
3. Check voltage between compressor (ECV) harness connector F6 terminal 2 and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10A fuse [No. 12, located in the fuse block (J/B)]. Refer to PG-77
.
If fuse is OK, check harness for open circuit. Repair or replace if necessary.
If fuse is NG, check harness for short circuit and replace fuse.
2.CHECK ECV CONTROL SIGNAL
1. Turn ignition switch OFF.
2. Reconnect compressor (ECV) connector.
3. Perform self-diagnosis. Refer to ATC-43, "
Self-Diagnosis Function".
4. Set in self-diagnosis STEP-4 (Code No. 45). Refer to ATC-43, "
Self-Diagnosis Function".
5. Confirm ECV control signal between unified meter and A/C amp. harness connector M57 terminal 45 and ground using an oscillo-
scope.
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive. Liquid tank or front/rear side of
expansion valve’s pipe is frost-
ed or wet with dew.High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.
If water is the cause, initially
cooling is okay. Then the wa-
ter freezes causing a block-
age. Drain water from
refrigerant or replace refrig-
erant.
If due to foreign particles, re-
move expansion valve and
remove the particles with dry
and compressed air (not
shop air).
If either of the above meth- ods cannot correct the mal-
function, replace expansion
valve.
Replace liquid tank.
Check lubricant for contami-
nation.
AC362A
2 – ground : Battery voltage
RJIA2294E
RJIA2295E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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TROUBLE DIAGNOSISATC-85
< SERVICE INFORMATION >
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Memory FunctionINFOID:0000000001328195
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
*1 AT C - 5 0 , "Operational Check"*2AT C - 5 2 , "Power Supply and Ground
Circuit for Auto Amp"
*3 AT C - 3 2 , "How to Perform Trouble Di-
agnosis for Quick and Accurate Re-
pair"
SJIA1803E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C
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ATC-86
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Ambient Sensor Circuit
INFOID:0000000001328196
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. It detects
ambient temperature and converts it into a resistance value which is
then input into the unified meter and A/C amp.
AMBIENT TEMPERATURE INPUT PROCESS
The unified meter and A/C amp. includes a processing circ uit for the ambient sensor input. However, when the
temperature detected by the ambient sensor increases quickly, the processing circuit retards the unified meter
and A/C amp. function. It only allows the unified mete r and A/C amp. to recognize an ambient temperature
increase of 0.33 °C (0.6 °F) per 100 seconds.
As an example, consider stopping fo r a few minutes after high speed driving. Although the actual ambient tem-
perature has not changed, the temperature detected by t he ambient sensor will increase. This is because the
heat from the engine compartment can radiate to the front grille area, location of the ambient sensor.
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR
*1AT C - 5 2 , "Power Supply and Ground
Circuit for Auto Amp"
*2AT C - 5 0 , "Operational Check"*3AT C - 4 3 , "Self-Diagnosis Function"
SJIA1595E
RJIA2016E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C