DESCRIPTION
The ambient temperature sensor is installed in front of the condenser. It detects the ambient temperature to control air conditioning AUTO mode. This sensor is connected to the A/C amplifier and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the A/C 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 A/C amplifier applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes.
DTC No. |
DTC Detection Condition |
Trouble Area |
---|---|---|
B1412/12 |
Open or short in ambient temperature sensor circuit |
|
WIRING DIAGRAM
PROCEDURE
1. |
READ VALUE USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body / Air Conditioner / Data List.
(e) Check the value(s) by referring to the table below.
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 displayed |
- |
OK:
The display is as specified in the Normal Condition column.
Result |
Proceed to |
---|---|
NG |
A |
OK (When troubleshooting according to Problem Symptoms Table) |
B |
OK (When troubleshooting according to the DTC) |
C |
B |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
C |
REPLACE A/C AMPLIFIER |
|
2. |
INSPECT AMBIENT TEMPERATURE SENSOR |
(a) Remove the ambient temperature sensor.
(b) Disconnect the ambient temperature sensor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
A4-1 - A4-2 |
10°C (50°F) |
3.00 to 3.73 kΩ |
A4-1 - A4-2 |
15°C (59°F) |
2.45 to 2.88 kΩ |
A4-1 - A4-2 |
20°C (68°F) |
1.95 to 2.30 kΩ |
A4-1 - A4-2 |
25°C (77°F) |
1.60 to 1.80 kΩ |
A4-1 - A4-2 |
30°C (86°F) |
1.28 to 1.47 kΩ |
A4-1 - A4-2 |
35°C (95°F) |
1.00 to 1.22 kΩ |
A4-1 - A4-2 |
40°C (104°F) |
0.80 to 1.00 kΩ |
A4-1 - A4-2 |
45°C (113°F) |
0.65 to 0.85 kΩ |
A4-1 - A4-2 |
50°C (122°F) |
0.50 to 0.70 kΩ |
A4-1 - A4-2 |
55°C (131°F) |
0.44 to 0.60 kΩ |
A4-1 - A4-2 |
60°C (140°F) |
0.36 to 0.50 kΩ |
NOTICE:
HINT:
As the temperature increases, the resistance decreases (see the graph).
Text in Illustration
*1 |
Component without harness connected (Ambient Temperature Sensor) |
*2 |
Sensing Portion |
NG |
REPLACE AMBIENT TEMPERATURE SENSOR |
|
3. |
CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - A/C AMPLIFIER) |
(a) Disconnect the A/C amplifier connector. |
|
(b) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
OK |
REPLACE A/C AMPLIFIER |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
System Diagram
SYSTEM DIAGRAM
Communication Table
Sender
Receiver
Signal
Line
Main Body ECU
(Driver Side Junction Block Assembly)
Clearance Warning ECU Assembly
Destination information
...
Precaution
PRECAUTION
1. PRECAUTION FOR VEHICLE WITH SRS AIRBAG AND SEAT BELT PRETENSIONER
(a) Some operations in this section may affect the SRS airbags. Prior to performing
the corresponding operations, read the precautions regarding the SRS airbags (See
page ). ...
Engine Hood Courtesy Switch Circuit
DESCRIPTION
The security courtesy switch is installed together with the hood lock. This switch
turns off when the engine hood is opened and turns on when the engine hood is closed.
WIRING DIAGRAM
PROCEDURE
1.
INSPECT HOOD LOCK AS ...