Coolant Temperature Sensor
- Check that sensor is properly installed and firmly seated. Check that cooling system is full. Bleed system. Check resistance between switch connections (between wire terminal and ground if single wire connector).
- Resistance should be within specification. See COOLANT TEMPERATURE SENSOR RESISTANCE table. If resistance is incorrect, replace sensor. If resistance is correct, check sensor wiring circuit and repair.
NOTE:
On 5 and 7 Series models with self-diagnostics, a short or open in the coolant temperature sensor will set a trouble code 45. If code is set, MCU will operate engine with preset coolant temperature value of 122°F (50°C).
COOLANT TEMPERATURE SENSOR RESISTANCE
| Application & Coolant Temperature | Ohms | |
|---|---|---|
| 2.5L & 3.5L | ||
| 12°F (-10°C) | 8200-10,500 | |
| 63-73°F (17-23°C) | 2300-2700 | |
| 171-181°F (77-83°C) | 300-360 | |