Pontiac Fiero 1988 Service Manual page 574

DRIVEABILITY AND EMISSIONS - FUEL INJECTION (TBI) 6E2-C12-1
SECTION C12
ELECTRIC COOLING FAN
CONTENTS
GENERAL DESCRIPTION C12-1 ON-CAR SERVICE C12-1
OPERATION C12-1 PARTS INFORMATION C12-1
DIAGNOSIS C12-1
GENERAL DESCRIPTION
All front wheel drive vehicles, with transversely
mounted engines, use an electric cooling fan. The fan
is used for engine and A/C condenser cooling and is
ECM controlled.
OPERATION
The ECM provides a ground path to energize the
fan relay, which turns "ON" the cooling fan. The ECM
will command the fan "ON", when coolant temp, is
above 108°C. When the engine cools down to about
101°C, the ECM de-energizes the fan relay, and the
fan stops. If the coolant sensor fails (Code 14 or 15
set), the ECM will command constant fan.
A/C equipped vehicles have a separate signal line
to the J2CM for fen^
switch is on and the low pressure switch closed, the
ECM receives a signal on this line and turns on the
fan. The A/C clutch does not have to engage for the
ECM to turn "ON" the fan.
DIAGNOSIS
The following charts will diagnose the ECM
controlled cooling fans. For specific system
components and wiring see the Electrical
Troubleshooting Manual.
ON-CAR SERVICE
Cooling system component replacement can be
found in Section "6B".
PARTS INFORMATION
PART NAME GROUP
Fan kit, Elec. Clg. 1.055
Motor kit, Elec Clg. Fan 1.055
Relay, Engine Fan 1.055