B1233

COMPONENT LOCATION





GENERAL DESCRIPTION

The incar temperature sensor located at crush pad, control unit contains a thermistor which measures the temperature of the inside. The signal, decided by the resistance value which changes in accordance with perceived inside temperature, is delivered to heater control unit and according to this signal, the control unit regulates incar temperature to intended value.

DTC DESCRIPTION

The A/C controller sets DTC B1233 if there is a short circuit in incar temp. sensor signal harness or the measured resistance value of sensor is less than threshold value(about 7.46kOhms)

DTC DETECTING CONDITION





SPECIFICATION





MONITOR SCANTOOL DATA

1. Connect scantool to data link connector(DLC).
2. Engine "ON"
3. Monitor the "INCAR TEMP. SENSOR" Parameter on the Scantool.




4. Are the DTC B1233 present and is parameter of "INCAR TEMP. SENSOR" fixed?
** Parameter of "INCAR TEMP. SENSOR" will be fixed at 25°C(77°F), if there is any fault in INCAR TEMP. SENSOR.
YES
Go to "Inspection" procedure.
NO
Fault is intermittent caused by poor contact in the sensor's and/or A/C controller's connector or was repaired and A/C controller memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

TERMINAL AND CONNECTOR INSPECTION

1. Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
Go to "Signal circuit inspection" procedure.

SIGNAL CIRCUIT INSPECTION

1. Check for short to ground in harness.
(1) Ignition "OFF"
(2) Disconnect incar sensor.
(3) Measure resistance between terminal "4" of incar sensor and chassis ground.

Specification : Approx. InfinityOhms





(4) Is the measured resistance within specifications?
YES
Go to "Component Inspection" procedure.
NO
Check for short to ground in harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION

1. Check incar temp. sensor.
(1) Ignition "OFF"
(2) Disconnect incar sensor.
(3) Measure resistance between terminal "4" and "2" of incar sensor.

Specification : Refer the specifications in fig 3.









(4) Is the measured resistance within specifications in fig3? (tolerance limits ± 3%)
YES
Go to "Check A/C Control Unit" procedure.
NO
Substitute with a known-good incar sensor and check for proper operation.
If the problem is corrected, replace incar sensor and then go to "Verification of Vehicle Repair" procedure.
2. Check A/C Control Unit
(1) Engine "ON"
(2) Disconnect incar sensor.
(3) Measure Voltage between terminal "5" of A/C Control Unit and chassis ground.

Specification : Approx. 5V





(4) Is the measured voltage within specifications?
YES
Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
Substitute with a known-good A/C Control Unit and check for proper operation.
If the problem is corrected, replace A/C Control Unit and then go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode and then clear DTC.
2. Operate the vehicle and monitor the DTC on the scantool.
3. Are any DTCs present?
YES
Go to the applicable troubleshooting procedure.
NO
System is performing to specification at this time.