Temperature Thermistor Test
The in-car temperature sensor uses a temperature thermistor to provide resistance values that correlate with temperature change. Test the thermistor as follows:
- Remove the in-car temperature sensor and place it on a workbench. Refer to SENSOR, TEMPERATURE, IN-CAR, REMOVAL AND INSTALLATION .
- Note the current ambient air temperature of the work area.
- Use an ohm meter and check the resistance between pins 1 and 2 of the in-car temperature sensor. Compare the temperature of the work area to the found resistance value. The resistance should be within specifications as listed in the Resistance and Temperature chart. If not OK, replace the in-car temperature sensor.
| RESISTANCE AND TEMPERATURE | ||
|---|---|---|
| AIR TEMPERATURE RANGE | LOW RESISTANCE RANGE (KILOHM) | HIGH RESISTANCE RANGE (KILOHM) |
| -21° to -15°C (-5° to 5°F) | 292 ± 1.0 | 223 ± 0.9 |
| -14° to -9°C (6° to 15°F) | 198 ± 0.9 | 161 ± 0.8 |
| -8° to -4°C (16° to 25°F) | 144 ± 0.8 | 123 ± 0.8 |
| -3° to 1°C (26° to 35°F) | 111 ± 0.7 | 95 ± 0.7 |
| 2 to 7°C (36° to 45°F) | 86 ± 0.7 | 70 ± 0.6 |
| 8 to 12°C (46° to 55°F) | 64 ± 0.6 | 55 ± 0.5 |
| 13° to 18°C (56° to 65°F) | 51 ± 0.5 | 42 ± 0.4 |
| 19° to 23°C (66° to 75°F) | 39 ± 0.4 | 33 ± 0.3 |
| 24° to 29°C (76° to 85°F) | 31 ± 0.3 | 26 ± 0.3 |
| 30° to 35°C (86° to 95°F) | 24 ± 0.3 | 20 ± 0.3 |
| 36° to 40°C (96° to 105°F) | 18 ± 0.3 | 16 ± 0.3 |
| 41° to 46°C (106° to 115°F) | 15 ± 0.3 | 13 ± 0.3 |