Sensor Resistance Test
- Remove the coolant temperature sensor. Refer to COOLANT TEMPERATURE SENSOR R & I under REMOVAL & INSTALLATION. Place sensor and thermometer in water. Measure resistance between sensor terminals No. 1 (Brown wire) and No. 3 (Light Green/Red wire), at specified temperatures. See COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS table.
- If resistance is not as specified, replace sensor. If resistance is within specification, inspect wiring harness and connectors between sensor and A/C-heater control panel. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute a known-good A/C-heater control panel, then retest system.
COOLANT TEMPERATURE SENSOR RESISTANCE SPECIFICATIONS
| Sensor Temperature °F (°C) |
Ohms |
| 32 (0) |
16,500-17,500 |
| 104 (40) |
2400-2800 |
| 158 (70) |
700-1000 |