DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
READ VALUE OF INTELLIGENT TESTER
INSPECT AIR CONDITIONING AMPLIFIER
INSPECT A/C ROOM TEMPERATURE SENSOR
CHECK HARNESS AND CONNECTOR (A/C ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)
DTC B1411/11 Room Temperature Sensor Circuit
DESCRIPTION
This sensor detects the cabin temperature that is used as the basis for temperature control and sends a signal to the A/C amplifier.
| DTC No. | DTC Detection Condition | Trouble Area |
| B1411/11 |
Room temperature sensor circuit (Open or short) |
Room temperature sensor
Harness or connector between room temperature sensor and A/C amplifier
A/C amplifier
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WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.READ VALUE OF INTELLIGENT TESTER |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the intelligent tester main switch on.
Select the item below in the Data List, and read the display on the intelligent tester.
Data List / Air Conditioner:| Item | Measurement Item / Display (Range) | Normal Condition | Diagnostic Note |
Room Temperature Sensor
(Room Temp) | Room temperature sensor / min.: -6.5°C (20.3°F), max.: 57.25°C (135.05°F) | Actual cabin temperature is displayed | - |
- OK:
- The display is as specified in the normal condition column.
- Result:
| Result | Proceed to |
| NG | A |
| OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE) | B |
| OK (When troubleshooting according to the DTC) | C |
| | PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
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| | REPLACE AIR CONDITIONING AMPLIFIER |
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| 2.INSPECT AIR CONDITIONING AMPLIFIER |
Remove the A/C amplifier with the connectors still connected.
Turn the engine switch on (IG).
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester Connection | Condition | Specified Condition |
| J58-16 (TR) - J58-19 (SG-1) | Engine switch on (IG) at 25°C (77°F) | 1.8 to 2.2 V |
| J58-16 (TR) - J58-19 (SG-1) | Engine switch on (IG) at 40°C (104°F) | 1.2 to 1.6 V |
- As the temperature increases, the voltage decreases.
- Result:
| Result | Proceed to |
| NG | A |
| OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE) | B |
| OK (When troubleshooting according to the DTC) | C |
| | PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
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| | REPLACE AIR CONDITIONING AMPLIFIER |
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| 3.INSPECT A/C ROOM TEMPERATURE SENSOR |
Remove the A/C room temperature sensor.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| J38-1 - J38-2 | 10°C (50°F) | 3.00 to 3.73 kΩ |
| J38-1 - J38-2 | 15°C (59°F) | 2.45 to 2.88 kΩ |
| J38-1 - J38-2 | 20°C (68°F) | 1.95 to 2.30 kΩ |
| J38-1 - J38-2 | 25°C (77°F) | 1.60 to 1.80 kΩ |
| J38-1 - J38-2 | 30°C (86°F) | 1.28 to 1.47 kΩ |
| J38-1 - J38-2 | 35°C (95°F) | 1.00 to 1.22 kΩ |
| J38-1 - J38-2 | 40°C (104°F) | 0.80 to 1.00 kΩ |
| J38-1 - J38-2 | 45°C (113°F) | 0.65 to 0.85 kΩ |
| J38-1 - J38-2 | 50°C (122°F) | 0.50 to 0.70 kΩ |
| J38-1 - J38-2 | 55°C (131°F) | 0.44 to 0.60 kΩ |
| J38-1 - J38-2 | 60°C (140°F) | 0.36 to 0.50 kΩ |
Hold the sensor only by its connector. Touching the sensor may change the resistance value.
When measuring, the sensor temperature must be the same as the ambient temperature.
- As the temperature increases, the resistance decreases (see the graph).
| | REPLACE A/C ROOM TEMPERATURE SENSOR |
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| 4.CHECK HARNESS AND CONNECTOR (A/C ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) |
Disconnect the connectors from the A/C room temperature sensor and A/C amplifier.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| J58-16 (TR) - J38-1 | Always | Below 1 Ω |
| J58-19 (SG-1) - J38-2 | Always | Below 1 Ω |
| J58-16 (TR) - Body ground | Always | 10 kΩ or higher |
| J58-19 (SG-1) - Body ground | Always | 10 kΩ or higher |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| OK | |
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| REPLACE AIR CONDITIONING AMPLIFIER |
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LEXUS IS250, IS220d / GSE20 ALE20
