Ignition "OFF"
Disconnect Incar temp.sensor and Connect A/C control unit main harness connector.
Measure resistance between Signal(+) terminal of Incar temp.sensor harness connector and Sensor ground harness connector. (Component side)
Specification : Refer the specifications in Fig.1)
Temperature(℃/℉)  | Resistance(㏀)  | Temperature(℃/℉)  | Resistance(㏀)  | 
-20/-4  | 285.6  | 20/68  | 37.4  | 
-10/-14  | 164.6  | 30/86  | 24.1  | 
0/32  | 97.7  | 40/104  | 15.9  | 
10/50  | 59.67  | 50/122  | 10.8  | 
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.
Is "resistance" display within specifications?
![]()  | ▶ Go to "Check A/C-ECU" procedure.  | 
![]()  | ▶ 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.  | 
Ignition "OFF"
Disconnect Incar temp.sensor and Connect A/C control unit main harness connector.
Ignition "ON"(ENGINE "OFF").
Measure voltage between Signal(+) terminal of Incar temp.sensor harness connector and chassis ground. (Component side)
Specification : approx. 5V
Is "voltage" display within specifications?
![]()  | ▶ 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.  | 
![]()  | ▶ 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.  |