Ignition "OFF"
Disconnect ambient sensor and Connect A/C control unit main harness connector.
Measure resistance between Signal(+) terminal of ambient sensor harness connector and Sensor ground harness connector. (Component side)
Specification : Refer the specifications in Fig.1)
Temperature(℃/℉) | Resistance(㏀) | Temperature(℃/℉) | Resistance(㏀) |
-20/-4 | 271.4 | 50/122 | 11 |
0/32 | 95.1 | 70/158 | 7.58 |
25/77 | 30 |
FIG.1) ※ Specifications : Resistance value of ambient 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 ambient sensor and check for proper operation. If the problem is corrected, replace ambient sensor and then go to "Verification of Vehicle Repair" procedure. |
Ignition "OFF"
Disconnect Ambient Temp. sensor (+) and Connect A/C control unit main harness connector.
Ignition "ON"(ENGINE "OFF").
Measure voltage between Signal(+) terminal of Ambient 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. |
