Chevrolet 2001 Impala Owner's Manual page 353

Underhood Fuse Block (Lower)
Some fuses are in a fuse block on the passenger's side of
the engine compartment. See "Engine Compartment
Overview" in the Index for more information on location.
Circuit Relay Description
FAN CONT #3 Secondary Cooling Fan
(Passenger's Side)
FAN CONT #2 Cooling Fan Control Relay
FAN CONT #1 Primary Cooling Fan
(Driver's Side)
6-66
Circuit Relay Description
IGN RELAY Ignition Relay
A/C CMPR HVAC Compressor
Maxi Fuses Description
IGN SW Ignition Switch
RT I/P #3 Rear Defogger, Audio System
U/HOOD #2 Ignition Relay, AIR Pump
COOLING Cooling Fans (Battery)
FANS
Mini Fuses Description
FAN Cooling Fan Control
CONT #2 & #3 Relays #2 & #3
FAN CONT #1 Cooling Fan Control Relays #1
AIR PMP RLY Air Induction Reaction Pump
Relay (Battery)
FUEL INJ Fuel Injectors
TRANS SOL Transmission Solenoids
A/C RLY HVAC Control Relay
(COIL)
ENG DEVICES Canister Purge Solenoid, Mass Air
Flow Sensor (MAF), AIR Pump
Relay & Valve Control
DFI MDL Direct Fire Ignition Module
OXY SEN Oxygen Sensors
(Pre and Post Converter)