Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM1000000026Z8C
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 - 11/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for TMC Made, and Gasoline Model, with Automatic Air Conditioning System): B141A15; Room Temperature Sensor Circuit Short to Battery or Open; 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 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 (5 V) 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.

READ VALUE USING GTS (ROOM TEMPERATURE SENSOR)

(a) Read the Data List according to the display on the GTS.

Body Electrical > Air Conditioner > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Room Temperature Sensor

Room temp. sensor (cooler thermistor)

-327.68 to 327.67°C

Actual cabin temperature displayed

Room temp. sensor (cooler thermistor) circuit malfunction

Body Electrical > Air Conditioner > Data List

Tester Display

Room Temperature Sensor

OK:

The display is as specified in the normal condition column.

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

2.

INSPECT ROOM TEMP. SENSOR (COOLER THERMISTOR)

Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; HEATING / AIR CONDITIONING: ROOM TEMPERATURE SENSOR: INSPECTION

NG

REPLACE ROOM TEMP. SENSOR (COOLER THERMISTOR)

OK

3.

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

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

I48-5 (TR) - Body ground

Ignition switch ON

Below 1 V

I48-3 (SG-1) - Body ground

Ignition switch ON

Below 1 V
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR