System Check

1. With engine cold and idling, move A/C selector switch, if equipped, to NORM. The coolant fan should run for 60 seconds at low speed. When A/C head pressure exceeds 275 psi, coolant fan runs at high speed and auxiliary coolant fan runs.
2. With engine coolant below operating temperature, move A/C selector switch to OFF. Coolant fan should turn off in a short period of time.
3. Run engine at fast idle for several minutes. When coolant temperature exceeds 213°F, ECM turns coolant fan on at low speed. When coolant temperature exceeds 226°F, coolant fan runs at high speed and auxiliary coolant fan runs.