Dtc B1412/12 Ambient Temperature Sensor Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
READ VALUE USING TECHSTREAM (AMBIENT TEMPERATURE SENSOR)
INSPECT AMBIENT TEMPERATURE SENSOR
CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)
DTC B1412/12 Ambient Temperature Sensor Circuit |
DESCRIPTION
The ambient temperature sensor is installed in the front part of the condenser to detect the ambient temperature and control the air conditioner. The sensor is connected to the air conditioning amplifier and detects fluctuations in the ambient temperature. This data is used for controlling the room temperature. The sensor sends a signal to the air conditioning amplifier. The resistance of the ambient temperature sensor changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases. The air conditioning amplifier applies a voltage (5 V) to the ambient temperature sensor and reads voltage changes as changes in the resistance of the ambient temperature sensor.DTC No.
| DTC Detection Condition
| Trouble Area
|
B1412/12
| Open or short in ambient temperature sensor circuit
| - Ambient temperature sensor
- Harness and connector between ambient temperature sensor and air conditioning amplifier
- Air conditioning amplifier
|
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.READ VALUE USING TECHSTREAM (AMBIENT TEMPERATURE SENSOR) |
Connect the Techstream to DLC3.
Turn the ignition switch ON.
Turn the tester on.
Select the following menus: Body Electrical / Air Conditioner / Data List / Ambient Temp Sensor
According to the display on tester, read the "Data List".
- Data List / Air Conditioner:
Tester Display
| Measurement Item/Range
| Normal Condition
| Diagnostic Note
|
Ambient Temp Sensor
| Ambient temperature sensor /
Min.: -23.3°C (-9.94°F)
Max.: 65.95°C (150.71°F)
| Actual ambient temperature is displayed
| Open circuit: -23.3°C (-9.94°F)
Short circuit: 65.95°C (150.71°F)
|
- OK:
- The display is as specified in the normal condition column.
- Result:
Result
| Proceed to
|
NG
| A
|
OK (When troubleshooting according to PROBLEM SYMPTOMS TABLE)
| B
|
OK (When troubleshooting according to the DTC output)
| C
|
| 2.INSPECT AMBIENT TEMPERATURE SENSOR |
Remove the ambient temperature sensor.
Measure the resistance.
- Standard resistance:
Tester Connection
| Condition
| Specified Condition
|
1 - 2
| 10°C (50°F)
| 3.00 to 3.73 kΩ
|
1 - 2
| 15°C (59°F)
| 2.45 to 2.88 kΩ
|
1 - 2
| 20°C (68°F)
| 1.95 to 2.30 kΩ
|
1 - 2
| 25°C (77°F)
| 1.60 to 1.80 kΩ
|
1 - 2
| 30°C (86°F)
| 1.28 to 1.47 kΩ
|
1 - 2
| 35°C (95°F)
| 1.00 to 1.22 kΩ
|
1 - 2
| 40°C (104°F)
| 0.80 to 1.00 kΩ
|
1 - 2
| 45°C (113°F)
| 0.65 to 0.85 kΩ
|
1 - 2
| 50°C (122°F)
| 0.50 to 0.70 kΩ
|
1 - 2
| 55°C (131°F)
| 0.44 to 0.60 kΩ
|
1 - 2
| 60°C (140°F)
| 0.36 to 0.50 kΩ
|
- NOTICE:
- Touching the sensor even slightly may change the resistance value. Be sure to hold the connector of the sensor.
- When measuring, the sensor temperature must be the same as the ambient temperature.
- HINT:
- As the temperature increases, the resistance decreases (see the graph on the left).
Reinstall the ambient temperature sensor.
| 3.CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) |
Disconnect the B5 ambient temperature sensor connector.
Disconnect the E8 air conditioning amplifier connector.
Measure the resistance.
- Standard resistance:
Tester Connection
| Specified Condition
|
B5-1 - E8-11 (SG-1)
| Below 1 Ω
|
B5-2 - E8-5 (TAM)
| Below 1 Ω
|
B5-1 - Body ground
| 10 kΩ or higher
|
B5-2 - Body ground
| 10 kΩ or higher
|
Reconnect the ambient temperature sensor connector.
Reconnect the air conditioning amplifier connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
