RM38T0EC _58 Vehicle Interior _104612 HEATING / AIR CONDITIONING _0601796 AIR CONDITIONING SYSTEM(for HEV Model) C

HEATING / AIR CONDITIONING  AIR CONDITIONING SYSTEM(for HEV Model)  B141A15  Room Temperature Sensor Circuit Short to Battery or Open  


DESCRIPTION

The cooler thermistor (room temperature sensor) is installed in the instrument panel to detect the cabin temperature, which is used to control the air conditioning system. The resistance of the cooler thermistor (room temperature sensor) changes in accordance with the cabin temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage to the cooler thermistor (room temperature sensor) and reads voltage changes due to changes in the resistance of the cooler thermistor (room temperature sensor).

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B141A15 Room Temperature Sensor Circuit Short to Battery or Open Diagnosis Condition:

Ignition switch ON


Malfunction Status:

Open or short in room temperature sensor circuit


Detection Time:

Continuously for 4 seconds or more


·

Cooler thermistor (room temperature sensor)

·

Harness or connector

·

Air conditioning amplifier assembly


Memorized

DTC Detection Condition Combination Table
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Ignition switch ON ○ ○
Malfunction Open in room temperature sensor circuit ○ -
Short in room temperature sensor circuit - ○
Detection Time Continuously for 4 seconds or more Continuously for 4 seconds or more
Trip Count 1 trip 1 trip

HINT:

If the conditions of either of these patterns are detected, a DTC will be stored


WIRING DIAGRAM

E368742E86
0.521,1.781 1.042,2.01 0.521,0.229 10 false I227 0.521,1.958 2.094,2.479 1.573,0.521 10 false Cooler Thermistor (Room Temperature Sensor) 4.646,1.802 4.979,2 0.333,0.198 10 false I48 4.656,1.969 7.146,2.156 2.49,0.188 10 false Air Conditioning Amplifier Assembly 2.146,0.667 2.323,0.885 0.177,0.219 10 false 1 2.156,1.156 2.333,1.375 0.177,0.219 10 false 2 4.615,1.156 4.771,1.344 0.156,0.188 10 false 3 4.625,0.667 4.813,0.854 0.188,0.188 10 false 5 4.813,0.677 5.063,0.865 0.25,0.188 10 false TR 4.802,1.156 5.208,1.344 0.406,0.188 10 false SG-1 5.656,0.271 5.948,0.469 0.292,0.198 11 false 5 V 6.313,0.781 6.563,0.969 0.25,0.188 10 false IC

PROCEDURE

1.CHECK COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)
a.

Disconnect the I227 cooler thermistor (room temperature sensor) thermistor connector.


b.

Measure the voltage according to the value(s) in the table below.

Standard Voltage:
Tester Connection Switch Condition Specified Condition
I227-1 - Body ground Ignition switch ON 0 to 5.5 V



Result:
Proceed to
OK
NG



OK

2.CLEAR DTC

NG

5.CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)
2.CLEAR DTC
a.

Clear the DTCs.

Body Electrical > Air Conditioner > Clear DTCs
50002 450

Result:
Proceed to
NEXT



NEXT

3.CHECK FOR DTC
3.CHECK FOR DTC
a.

Turn the ignition switch off.


b.

Connect terminals 1 and 2 of the cooler (room temp. sensor) thermistor connector on the wire harness side.

E446844C52
4.427,1.271 4.844,1.51 0.417,0.24 1.094,2.042 1.417,2.344 0.323,0.302 10 false *1 3.104,2.031 3.427,2.333 0.323,0.302 10 false *2 4.802,0.531 5.125,0.833 0.323,0.302 10 false *a 2.604,1.042 2.927,1.344 0.323,0.302 10 false TR 2.458,1.427 3.073,1.781 0.615,0.354 10 false SG-1 4.5,1.302 5.115,1.656 0.615,0.354 10 false I227
*1 Cooler (Room Temp. Sensor) Thermistor *2 Air Conditioning Amplifier Assembly
*a Front view of wire harness connector
(to Cooler (Room Temp. Sensor) Thermistor) 		- -



c.

Turn the ignition switch to ON and wait for 4 seconds or more.


d.

Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes
50001 450

Result:
Result Proceed to
B141A11 is output A
B141A15 is output B



A

REPLACE COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

Click hereVehicle Interior>HEATING / AIR CONDITIONING>ROOM TEMPERATURE SENSOR>REMOVAL


B

4.CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)
4.CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)
a.

Disconnect the I48 air conditioning amplifier assembly connector.


b.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
Tester Connection Condition Specified Condition
I227-1 - I48-5 (TR) Always Below 1 Ω
I227-2 - I48-3 (SG-1) Always Below 1 Ω



c.

Measure the voltage according to the value(s) in the table below.

Standard Voltage:
Tester Connection Switch Condition Specified Condition
I227-1 - Body ground Ignition switch ON Below 1 V
I227-2 - Body ground Ignition switch ON Below 1 V



Result:
Proceed to
OK
NG



OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

Click hereVehicle Interior>HEATING / AIR CONDITIONING>AIR CONDITIONING AMPLIFIER>REMOVAL


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)
a.

Disconnect the I48 air conditioning amplifier assembly connector.


b.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:
Tester Connection Condition Specified Condition
I227-1 or I48-5 (TR) - Other terminals and body ground Always Below 1 Ω



Result:
Proceed to
OK
NG



OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

Click hereVehicle Interior>HEATING / AIR CONDITIONING>AIR CONDITIONING AMPLIFIER>REMOVAL


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR