Page 556 of 4647

TROUBLE DIAGNOSIS
ATC-105
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AT C
Revision: 2007 April2007 M35/M45
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low and
low-pressure side is too high.High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.Replace compressor.
No temperature difference
between high- and low-pres-
sure sides.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.Replace compressor.
AC356A
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low.
There is a big temperature
difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.
Liquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is slightly
clogged.
Replace liquid tank.
Check lubricant for contami-
nation.
Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.
Expansion valve inlet is
frosted.
Temperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquid tank and
expansion valve is clogged.
Check and repair malfunc-
tioning parts.
Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or slightly cool
when touched.Low refrigerant charge.
↓
Leaking fittings or compo-
nents.Check refrigerant for leaks.
Refer to ATC-169, "
Checking
for Refrigerant Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion valve
adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be
clogged.
Remove foreign particles by
using compressed air.
Replace expansion valve.
Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.
Check and repair malfunc-
tioning parts.
Check lubricant for contami-
nation.
Air flow volume is not enough
or is too low.Evaporator is frozen.
Check intake sensor circuit.
Refer to ATC-121, "
Intake
Sensor Circuit" .
Replace compressor.
Repair evaporator fins.
Replace evaporator.
Refer to AT C - 8 8 , "Blower
Motor Circuit" .
AC353A
Page 559 of 4647
ATC-108
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Insufficient HeatingNJS000GW
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-65, "Operational Check"*2AT C - 8 2 , "Air Mix Door Motor Circuit"*3ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to
6.
*4ATC-57, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.*5AT C - 7 1 , "
LAN System Circuit"*6ATC-88, "Blower Motor Circuit"
*7EC-214, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-926,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE)*8CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-40, "
Changing
Engine Coolant" (VK45DE)*9CO-16, "
Checking Radiator Cap"
(VQ35DE) or CO-45, "
Checking
Radiator Cap" (VK45DE)
RJIA4084E
Page 563 of 4647

ATC-112
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Ambient Sensor CircuitNJS000H0
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a resis-
tance 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 bumper 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 E62
terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA4087E
RJIA4088E
1 – Ground : Approx. 5 V
RJIA2017E
Page 564 of 4647

TROUBLE DIAGNOSIS
ATC-113
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AT C
Revision: 2007 April2007 M35/M45
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
E62 terminal 2 and unified meter and A/C amp. harness connec-
tor M65 terminal 61.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK AMBIENT SENSOR
Refer to AT C - 11 4 , "
Ambient Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp.
2. Go to self-diagnosis AT C - 5 7 , "
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 7 , "
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
E62 terminal 1 and unified meter and A/C amp. harness connec-
tor M65 terminal 45.
4. Check continuity between ambient sensor harness connector
E62 terminal 1 and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp.
2. Go to self-diagnosis AT C - 5 7 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> Repair harness or connector.2 – 61 : Continuity should exist.
RJIA4089E
1 – 45 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA4090E
Page 565 of 4647
ATC-114
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
COMPONENT INSPECTION
Ambient Sensor
After disconnecting ambient sensor connector E62, measure resis-
tance between terminals 1 and 2 at sensor side. Refer to the table
below.
If NG, replace ambient sensor.
Temperature °C (°F) Resistance kΩ
−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
RJIA4091E
Page 566 of 4647
TROUBLE DIAGNOSIS
ATC-115
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AT C
Revision: 2007 April2007 M35/M45
In-vehicle Sensor CircuitNJS000H1
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
assembly. It produces vacuum pressure due to air discharged from
the heater & cooling unit assembly, continuously taking compartment
air in the aspirator.
RJIA4092E
RJIA4093E
RJIA1804E
Page 567 of 4647

ATC-116
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR
SYMPTOM: In-vehicle sensor circuit is open or shorted. (22 or −22 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND
1. Disconnect in-vehicle sensor connector.
2. Turn ignition switch ON.
3. Check voltage between in-vehicle sensor harness connector
M54 terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE 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 in-vehicle sensor harness connector
M54 terminal 2 and unified meter and A/C amp. harness con-
nector M65 terminal 60.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3. CHECK IN-VEHICLE SENSOR
Refer to AT C - 11 7 , "
In-vehicle Sensor" .
OK or NG
OK >> 1. Replace unified meter and A/C amp.
2. Go to self-diagnosis AT C - 5 7 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> 1. Replace in-vehicle sensor.
2. Go to self-diagnosis AT C - 5 7 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
RJIA4094E
1 – Ground : Approx. 5 V
RJIA2022E
2 – 60 : Continuity should exist.
RJIA4095E
Page 568 of 4647

TROUBLE DIAGNOSIS
ATC-117
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AT C
Revision: 2007 April2007 M35/M45
4. CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE 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 in-vehicle sensor harness connector
M54 terminal 1 and unified meter and A/C amp. harness con-
nector M65 terminal 44.
4. Check continuity between in-vehicle sensor harness connector
M54 terminal 1 and ground.
OK or NG
OK >> 1. Replace unified meter and A/C amp.
2. Go to self-diagnosis AT C - 5 7 , "
FUNCTION CONFIRMATION PROCEDURE" and perform self-
diagnosis STEP-2. Confirm that code No. 20 is displayed.
NG >> Repair harness or connector.
COMPONENT INSPECTION
In-vehicle Sensor
After disconnecting in-vehicle sensor connector M54, measure resis-
tance between terminals 1 and 2 at sensor side. Refer to the table
below.
If NG, replace in-vehicle sensor.1 – 44 : Continuity should exist.
1 – Ground : Continuity should not exist.
RJIA4096E
Temperature °C (°F) Resistance kΩ
−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
RJIA4097E