1. Engine coolant temperature sensor inspection
The ECM engine coolant temperature sensor is a thermistor type sensor which has a characteristic of decreasing electrical resistance as the temperature rises.
1) Measure the resistance between the engine coolant temperature sensor terminals while changing the temperature using a DMM.
Note
- Confirm that the resistance and the values in the graph indicating the thermistor characteristics match.
- Replace the engine coolant temperature sensor if a malfunction is found.
Caution
- Do not allow water to enter the terminal section.
| Temperature |
Resistance |
| 130 ℃ { 266 °F } |
93 Ω |
| 120 ℃ { 248 °F } |
116.3 Ω |
| 110 ℃ { 230 °F } |
147.1 Ω |
| 100 ℃ { 212 °F } |
188.4 Ω |
| 90 ℃ { 194 °F } |
244.6 Ω |
| 80 ℃ { 176 °F } |
322.2 Ω |
| 70 ℃ { 158 °F } |
431.1 Ω |
| 60 ℃ { 140 °F } |
586.5 Ω |
| 50 ℃ { 122 °F } |
812.6 Ω |
| 40 ℃ { 104 °F } |
1,148 Ω |
| 30 ℃ { 86 °F } |
1,658 Ω |
| 20 ℃ { 68 °F } |
2,450 Ω |
| 10 ℃ { 50 °F } |
3,714 Ω |
| 0 ℃ { 32 °F } |
5,790 Ω |
| -10 ℃ { 14 °F } |
9,308 Ω |
| -20 ℃ { -4 °F } |
15,480 Ω |
| -30 ℃ { -22 °F } |
26,740 Ω |
| -40 ℃ { -40 °F } |
48,140 Ω |
2) Remove any water droplet adhering to the engine coolant temperature sensor.