B1412
HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Hatchback): B1412: Ambient Temperature Sensor Circuit
B1412 - Ambient Temperature Sensor Circuit
DESCRIPTION
The thermistor assembly (ambient temperature sensor) is installed in the front part of the cooler condenser assembly to detect the ambient temperature and control the air conditioning auto mode. The sensor connected to the combination meter assembly detects fluctuations in the ambient temperature. This data is used for controlling the room temperature. The sensor sends a signal to the combination meter assembly. The resistance of the thermistor assembly (ambient temperature sensor) changes in accordance with the cooler thermistor temperature (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 (ambient temperature sensor) and reads voltage changes as changes in the resistance of the thermistor assembly (ambient temperature sensor). The combination meter assembly sends these signals to the air conditioning amplifier assembly.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK FOR DTC (CAN COMMUNICATION SYSTEM)
(a) Use the Techstream to check if the CAN communication system is functioning normally.
OK:
CAN DTC is not output
Result
B -- GO TO CAN COMMUNICATION SYSTEM How To Proceed With Troubleshooting (from 07/2011)
C -- GO TO CAN COMMUNICATION SYSTEM How To Proceed With Troubleshooting (from 07/2011)
A -- Continue to next step.
2. 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 Electrical / Combination Meter / Data List.
(e) According to the display on the Techstream, read the Data List.
Combination Meter
OK:
The display is as specified in the normal condition column.
NG -- INSPECT THERMISTOR ASSEMBLY (AMBIENT TEMPERATURE SENSOR)
OK -- Continue to next step.
3. 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 Electrical / Air Conditioner / Data List.
(e) According to the display on the Techstream, read the Data List.
Air Conditioner
OK:
The display is as specified in the normal condition column.
Result
B -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures
C -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal (from 07/2011)
A -- Continue to next step.
4. CHECK FOR DTC
(a) Clear the DTCs DTC Check / Clear (from 07/2011).
(b) Check for DTCs DTC Check / Clear (from 07/2011).
OK:
DTC B1412 is not output
NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK -- USE SIMULATION METHOD TO CHECK Electronic Circuit Inspection Procedure
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
(a) Temporarily replace the air conditioning amplifier assembly with a new or normally functioning one Removal (from 07/2011).
NEXT -- Continue to next step.
6. CHECK FOR DTC
(a) Clear the DTCs DTC Check / Clear (from 07/2011).
(b) Check for DTCs DTC Check / Clear (from 07/2011).
OK:
DTC B1412 is not output
NG -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)
OK -- END (AIR CONDITIONING AMPLIFIER ASSEMBLY IS FAULTY)
7. INSPECT THERMISTOR ASSEMBLY (AMBIENT TEMPERATURE SENSOR)
(a) Inspect the thermistor assembly (ambient temperature sensor) Testing and Inspection.
NG -- REPLACE THERMISTOR ASSEMBLY (AMBIENT TEMPERATURE SENSOR) Removal (from 07/2011)
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (THERMISTOR ASSEMBLY (AMBIENT TEMPERATURE SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)
(a) Disconnect the A61 thermistor assembly (ambient temperature sensor) connector.
(b) Disconnect the D100 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)