Q: How to test and replace the engine cooling fan and relay on my Toyota Matrix and Pontiac Vibe?
A: The Radiator Fan Assembly on these models is controlled by the Powertrain Control Module (PCM) through inputs from the Coolant Temperature Sensor. To test an inoperative fan motor, check the fuses or fusible links first, then disconnect the electrical connector and use fused jumper wires to connect the fan directly to the battery. If the fan still doesn't work, replace the fan motor. If the motor tested okay but is still inoperative, the fault may lie in the relays, fuse, wiring, coolant temperature sensor, or PCM. To remove the fan, disconnect the battery cable, wiring connector, and coolant overflow hose, then unbolt the fan shroud from the radiator and lift the fan/shroud/coolant reservoir assembly from the vehicle. Hold the fan blades and remove the fan retaining nut (and spacer, if equipped), then unbolt the fan motor from the shroud. Installation is the reverse of removal.