DESCRIPTION
The thermistor assembly is installed in front of the cooler condenser assembly to detect the ambient temperature, which is used to control the air conditioning system. This sensor is connected to the combination meter assembly and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the combination meter assembly. The resistance of the thermistor assembly changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The combination meter assembly applies a voltage (5 V) to the thermistor assembly and reads voltage changes due to changes in the resistance of the thermistor assembly.
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Memory |
---|---|---|---|---|
B1412 |
Ambient Temperature Sensor Circuit |
When the air conditioning amplifier assembly receives out-of-range outside temperature sensor data from the combination meter assembly. |
|
Memorized (4 seconds or more)* |
HINT:
If the ambient temperature is approximately -80.0°C (-112°F) or lower, DTC B1412 may be output even though the system is normal.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.
PROCEDURE
1. |
CHECK CAN COMMUNICATION SYSTEM |
(a) Check if CAN communication DTCs are output.
Click here
Result |
Proceed to |
---|---|
CAN communication DTCs are not output. |
A |
CAN communication DTCs are output. |
B |
B | ![]() |
GO TO CAN COMMUNICATION SYSTEM |
|
2. |
READ VALUE USING TECHSTREAM (AMBIENT TEMPERATURE) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Combination Meter / Data List.
(e) Read the Data List according to the display on the Techstream.
Body Electrical > Combination Meter > Data List
Tester Display |
Measurement Item |
Range |
Normal Condition |
Diagnostic Note |
---|---|---|---|---|
Ambient Temperature |
Outside temperature |
Min.: -40°C (-40°F) Max.: 87.5°C (189.5°F) |
Almost the same as actual outside temperature |
The temperature displayed on the multi-information display is -40 to 50°C (-40 to 122 °F) |
Tester Display |
---|
Ambient Temperature |
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 | ![]() |
AIR CONDITIONING AMPLIFIER ASSEMBLY |
C | ![]() |
GO TO STEP 5 |
|
3. |
INSPECT THERMISTOR ASSEMBLY |
(a) Remove the thermistor assembly.
Click here
(b) Inspect the thermistor assembly.
Click here
NG | ![]() |
REPLACE THERMISTOR ASSEMBLY |
|
4. |
CHECK HARNESS AND CONNECTOR (THERMISTOR ASSEMBLY - COMBINATION METER ASSEMBLY) |
(a) Disconnect the A3 thermistor assembly connector.
(b) Disconnect the F4 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
F4-34 (TEMP) - A3-2 |
Always |
Below 1 Ω |
F4-35 (TX1+) - A3-1 |
Always |
Below 1 Ω |
F4-34 (TEMP) or A3-2 - Body ground |
Always |
10 kΩ or higher |
F4-35 (TX1+) or A3-1 - Body ground |
Always |
10 kΩ or higher |
OK | ![]() |
REPLACE COMBINATION METER ASSEMBLY |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
5. |
CHECK FOR DTC |
(a) Clear the DTCs.
Click here
(b) Check for DTCs.
Click here
Result |
Proceed to |
---|---|
DTCs are not output |
A |
DTCs are output |
B |
A | ![]() |
USE SIMULATION METHOD TO CHECK |
B | ![]() |
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
Toyota CH-R Service Manual > Air Conditioning System(for Automatic Air Conditioning System With Side-mounted
Air Conditioner Pressure Sensor): Communication Malfunction (Bus Ic) (B1497)
DESCRIPTION
The air conditioning harness assembly connects the air conditioning amplifier
assembly and the servo motors. The air conditioning amplifier assembly supplies
power and sends operation instructions to each servo motor through the air conditioning
harness assembly. Each servo motor ...
Toyota CH-R Owners Manual > Driving procedures: Continuously variable transmission
Shifting the shift lever
Vehicles
without a smart key system: While the engine switch is in the "ON" position and
the brake pedal depressed*, shift the shift lever while pushing the shift release
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Vehicles with a smart key system: While the engine swi ...