Component Inspection

Air Conditioner

B1233 In-car temperature sensor short (Low) - Component Inspection

Component Inspection

Check Incar temp. sensor
1. Ignition "OFF".
2. A/C-ECU, Incar temp. sensor : Connect.
3. Measure resistance between Signal (+) terminal of Incar temp. sensor harness connector and and Sensor ground harness connector. (Component side)
A. Specification : Refer the specifications in fig.1








FIG.1) ** Specifications : Resistance value of incar sensor as a function of temperature.
** The actual value may differ from it according to various engine condition.
4. Is "resistance" display near the specified value?
YES
1) Go to "Check A/C-ECU" procedure.
NO
1) Substitute with a known-good Incar temp. sensor and check for proper operation. If the problem is corrected, replace Incar temp. sensor and then go to "Verification of Vehicle Repair" procedure.
Check A/C-ECU
1. Ignition "OFF"
2. A/C-ECU : Connect, Incar temp. sensor : Disconnect.
3. Ignition "ON"(ENGINE "OFF").
4. Measure voltage between Signal (+) terminal of Incar temp. sensor harness connector and and chassis ground. (Component side)
A. Specification : Approx. 5 V




5. Is "voltage" display near the specified value?
YES
1) 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
1) Substitute with a known-good A/C-ECU and check for proper operation. If the problem is corrected, replace A/C-ECU and then go to "Verification of Vehicle Repair" procedure.