DTC B141A-15: Room Temperature Sensor Circuit Short to Battery or Open [10/2022 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK ROOM TEMP. SENSOR (COOLER THERMISTOR) CIRCUIT
Pre-procedure1
- Disconnect the C57 room temp. sensor (cooler thermistor) connector.
*a Front view of wire harness connector
(to Room Temp. Sensor (Cooler Thermistor))
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition Result C57-1 (+) - Body ground Ignition switch ON 0 to 5.5 V V Result
Proceed to OK NG
Post-procedure1
- None
Result:
NG
See step 5
Result:
OK
See step 2
- Disconnect the C57 room temp. sensor (cooler thermistor) connector.
- CLEAR DTC
Result:
NEXT
See step 3
- CHECK FOR DTC
Pre-procedure1
- Turn the ignition switch off.
- Disconnect the C57 room temp. sensor (cooler thermistor) connector.
*a Front view of wire harness connector
(to Room Temp. Sensor (Cooler Thermistor)) - 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 - Turn the ignition switch to ON and wait for 4 seconds or more.
- Check for DTCs.
Body Electrical > Air Conditioner > Trouble Codes
Result
Result Proceed to B141A-11 is output A B141A-15 is output B
Post-procedure1
- None
Result:
A
REPLACE ROOM TEMP. SENSOR (COOLER THERMISTOR). Refer to REMOVAL [10/2022 - ]
Result:
B
See step 4
- CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - ROOM TEMP. SENSOR (COOLER THERMISTOR))
Pre-procedure1
- Disconnect the C57 room temp. sensor (cooler thermistor) connector.
- Disconnect the C48 air conditioning amplifier assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result C57-1 (+) - C48-5 (TR) Always Below 1 Ω Ω C57-2 (-) - C48-3 (SG-1) Always Below 1 Ω Ω Result
Proceed to OK NG
Post-procedure1
- None
Result:
OK
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to REMOVAL [10/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - ROOM TEMP. SENSOR (COOLER THERMISTOR))
Pre-procedure1
- Disconnect the C57 room temp. sensor (cooler thermistor) connector.
- Disconnect the C48 air conditioning amplifier assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result C57-1 (+) or C48-5 (TR) - Other terminals and body ground Always 10 kΩ or higher kΩ Result
Proceed to OK NG
Post-procedure1
- None
Result:
OK
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to REMOVAL [10/2022 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR