Radiator Fan Control
Fan control is accomplished three ways. The fan runs when the air conditioning pressure reaches a set pressure, refer to RADIATOR FAN OPERATION chart. In addition to this control, the fan is turned on by the temperature of the coolant which is sensed by the coolant temperature sensor which sends the message to the Powertrain Control Module (PCM). The PCM turns on the fan through a fan relay. On models equipped with automatic transmission, a transmission fluid thermistor may have some influences on fan operation. See appropriate Wiring Diagrams Information for circuity and diagnostics provided.
The Powertrain Control Module (PCM) provides fan control for the following conditions:
- The fan will not run during cranking until the engine starts no matter what the coolant temperature is.
- Fan will run when the air conditioning clutch is engaged, and once set compressor head pressure is reached. See following charts.
- Fan will run according to the following information charts.
RADIATOR FAN OPERATION
| Radiator Fan Control | A/C Pressure | |||
|---|---|---|---|---|
| A/C Off | Low | High | N/A | N/A |
| Fan On: | 104°C (219°F) | 110°C (230°F) | N/A | N/A |
| Fan Off: | 99°C (210°F) | 105°C (221°F) | N/A | N/A |
| A/C On | Low | High | Low | High |
| Fan On: | 99°C (210°F) | 110°C (230°F) | 1, 448 kPa (210 psi) | 1, 718 kPa (249 psi) |
| Fan Off: | 93°C (199°F) | 105°C (221°F) | 1, 207 kPa (175 Psi) | 1, 585 kPa (229 Psi) |
| EATX Fluid Temperature | Low Speed | High Speed |
|---|---|---|
| Fan On: | 109°C (228°F) | 111°C (232°F) |
| Fan Off: | 104°C (220°F) | 109°C (228°F) |
| EATX Fluid Temperature | Low Speed | High Speed |
|---|---|---|
| Fan On: | 109°C (228°F) | 111°C (232°F) |
| Fan Off: | 104°C (220°F) | 109°C (228°F) |