Ignition "OFF"
Disconnect engine coolant temperature sensor and Connect A/C control Module main harness connector.
Measure resistance between Signal(+) terminal of engine coolant temperature sensor harness connector and Sensor ground harness connector.
Specification : Refer the specifications in fig.1)
Temperature(℃/℉) | Resistance(㏀) | Temperature(℃/℉) | Resistance(㏀) |
-10/-14 | 45.9 | 40/104 | 3.27 |
0/32 | 25 | 60/140 | 1.4 |
20/68 | 8.43 | 80/176 | 0.7 |
Fig.1) Resistance value of engine coolant temperature sensor as a function of temperature.
Is "resistance" display near the specified value?
 | ▶ Go to Next procedure. |
 | ▶ Substitute with a known-good engine coolant temperature sensor and check for proper operation. If the problem is corrected, replace engine coolant temperature sensor and then go to "Verification of Vehicle Repair" procedure. |
Ignition "OFF"
Disconnect engine coolant temperature sensor and Connect A/C control Module main harness connector.
Ignition "ON"(ENGINE "OFF").
Measure voltage between Signal(+) terminal of engine coolant temperature sensor harness connector and chassis ground.
Specification : approx. 5V
Is "voltage" display near the specified value?
| ▶ 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 control Module and check for proper operation. If the problem is corrected, replace A/C control Module and then go to "Verification of Vehicle Repair" procedure. |
