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ATC-100
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Insufficient HeatingAJS00150
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-61, "Operational Check"*2AT C - 7 3 , "Air Mix Door Motor Circuit"*3ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to
6.
*4 ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13. *5
AT C - 6 6 , "
LAN System Circuit"*6ATC-79, "Blower Motor Circuit"
*7 EC-208, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-914,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE) *8
CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-37, "
Changing
Engine Coolant" (VK45DE) *9
CO-15, "
Checking Radiator Cap"
(VQ35DE) or CO-43, "
Checking
Radiator Cap" (VK45DE)
RJIA2013E
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TROUBLE DIAGNOSIS ATC-101
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
NoiseAJS00151
SYMPTOM: Noise
INSPECTION FLOW
RJIA3108E
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ATC-102
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Self-diagnosisAJS00152
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1 Compressor Clutch, ATC-144,
"REMOVAL"
*2 Compressor Clutch, ATC-146,
"INSTALLATION"
*3AT C - 2 7 , "Maintenance of Lubricant
Quantity in Compressor"
*4ATC-61, "Operational Check"*5 EM-15, "Checking Drive Belts"
(VQ35DE) or EM-173, "
Checking
Drive Belts" (VK45DE)
*1 ATC-63, "
Power Supply and Ground
Circuit for Auto Amp."
*2 ATC-104, "Ambient Sensor Circuit"*3ATC-107, "In-vehicle Sensor Circuit"
*4ATC-110, "Sunload Sensor Circuit"*5 ATC-113, "Intake Sensor Circuit"*6AT C - 7 3 , "Air Mix Door Motor Circuit"
*7ATC-61, "Operational Check"*8 ATC-42, "SYMPTOM TABLE"
RJIA2014E
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TROUBLE DIAGNOSIS ATC-103
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
Memory FunctionAJS00153
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
*1AT C - 6 3 , "Power Supply and Ground
Circuit for Auto Amp."
*2ATC-61, "Operational Check"*3 AT C - 5 4 , "FUNCTION CONFIRMA-
TION PROCEDURE"
RJIA2015E
Page 541 of 4731

ATC-104
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Ambient Sensor CircuitAJS00154
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 circuit 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 meter 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 for a few minutes after high speed driving. Although the actual ambient tem-
perature has not changed, the temperature detected by the 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
SYMPTOM: Ambient sensor circuit is open or shorted. (21 or −21 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E34 terminal 1 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA2016E
RJIA1461E
1 – Ground : Approx. 5 V
RJIA2017E
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TROUBLE DIAGNOSIS ATC-105
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
2. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between ambient sensor harness connector E34 terminal 2 (W) and unified meter and A/C amp. harness
connector M57 terminal 49 (W/G).
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to ATC-106, "
Ambient Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> 1. Replace ambient sensor. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
4. CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.
1. Turn ignition switch OFF.
2. Disconnect unified meter and A/C amp. connector.
3. Check continuity between ambient sensor harness connector E34 terminal 1 (Y) and unified meter and A/C amp. harness con-
nector M57 terminal 39 (Y).
4. Check continuity between ambient sensor harness connector E34 terminal 1 (Y) and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp. 2. Go to self-diagnosis AT C - 5 4 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> Repair harness or connector. 2 – 49 : Continuity should exist.
RJIA2018E
1 – 39 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA2019E
Page 543 of 4731
ATC-106
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor connector E34, measure resis-
tance between terminals 1 and 2 at sensor side, using the table
below.
If NG, replace ambient sensor.
Temperature °C ( °F) Resistance k Ω
− 15 (5) 12.73
− 10 (14) 9.92
− 5 (23) 7.80
0 (32) 6.19
5 (41) 4.95
10 (50) 3.99
15 (59) 3.24
20 (68) 2.65
25 (77) 2.19
30 (86) 1.81
35 (95) 1.51
40 (104) 1.27 45 (113) 1.07
RJIA2020E
Page 544 of 4731
TROUBLE DIAGNOSIS ATC-107
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
In-vehicle Sensor CircuitAJS00155
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on instrument driver lower panel. It
converts variations in temperature of compartment air drawn from
the aspirator into a resistance value. It is then input into the unified
meter and A/C amp.
Aspirator
The aspirator is located on driver’s side of heater & cooling unit. It
produces vacuum pressure due to air discharged from the heater &
cooling unit, continuously taking compartment air in the aspirator.
RJIA2021E
RJIA0921E
RJIA1804E