Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000028C3O
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [11/2022 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System): B141A15; Room Temperature Sensor Circuit Short to Battery or Open; 2023 - 2025 MY Corolla Corolla Hatchback GR Corolla [11/2022 -        ]

DTC

B141A15

Room Temperature Sensor Circuit Short to Battery or Open

DESCRIPTION

The room temp. sensor (cooler thermistor) is installed in the instrument panel to detect the cabin temperature, which is used to control the air conditioning system. The resistance of the room temp. sensor (cooler thermistor) 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 room temp. sensor (cooler thermistor) and reads voltage changes due to changes in the resistance of the room temp. sensor (cooler thermistor).

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:

  • Open or short (+B) in room temperature sensor circuit

Detection Time:

  • Continuously for 4 seconds or more
  • Room temp. sensor (cooler thermistor)
  • 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 (+B) 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

PROCEDURE

1.

CHECK ROOM TEMP. SENSOR (COOLER THERMISTOR) CIRCUIT

(a) Disconnect the I36 room temp. sensor (cooler thermistor) connector.

*a

Front view of wire harness connector

(to Room Temp. Sensor (Cooler Thermistor))

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I36-1 - Body ground

Ignition switch ON

0 to 5.5 V

NG

GO TO STEP 5

OK

2.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Air Conditioner > Clear DTCs

NEXT

3.

CHECK FOR DTC

(a) Turn the ignition switch off.

(b) Disconnect the I36 room temp. sensor (cooler thermistor) connector.

*a

Front view of wire harness connector

(to Room Temp. Sensor (Cooler Thermistor))

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

*1

Room Temp. Sensor (Cooler Thermistor)

*2

Air Conditioning Amplifier Assembly

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

(e) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result

Proceed to

B141A11 is output

A

B141A15 is output

B

A

REPLACE ROOM TEMP. SENSOR (COOLER THERMISTOR)

B

4.

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

(a) Disconnect the I36 room temp. sensor (cooler thermistor) connector.

(b) Disconnect the I48 air conditioning amplifier assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I36-1 - I48-5 (TR)

Always

Below 1 Ω

I36-2 - I48-3 (SG-1)

Always

Below 1 Ω

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.

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

(a) Disconnect the I36 room temp. sensor (cooler thermistor) connector.

(b) Disconnect the I48 air conditioning amplifier assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

I36-1 or I48-5 (TR) - Other terminals and body ground

Always

10 kΩ or higher

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR