Precision Turbo and Engine BigStuff3 GEN3 PRO SEFI (LS1) System Hardware & BigComm Software - Manual (Page 14)

BigStuff3 Pro SEFI System (LS1)
Version 1.0 13
H20 – (Black, 2-way Packard connector)
This connector mates with a GM style coolant temperature sensor (front driver’s side cylinder
head).
Back_to_H2O
Air – (Gray, 2-way Packard connector)
This connector mates with a GM style air temperature sensor in the inlet duct between the air
cleaner and the throttle body.
Back_to_Air_Temp
IAC (Idle/Air Control) – (Black, 4-way Packard connector)
The main harness IAC connector was designed to work with a GM style IAC motor and valve
assembly with an in-line 1-by-4 connector.
Alternatively, the factory installed 1-by-4 in-line connector can be removed and replaced with a
2-by-2 connector per the pin-out table below.
LS1 In-line, 1-by-4, IAC
Connector Pin-out
IAC Coils
Late Model 2-by-2 IAC
Connector Pin-out
D A-Hi A
C A-Lo B
B B-Hi C
A B-Lo D
Back_to_IAC
TPS (Throttle Position Sensor) – (Black, 3-way Packard connector)
Connect the TPS connector to the LS1 throttle
position sensor, located on the engine throttle
body.
Alternatively, the factory installed TPS
connector can be removed and replaced with a
late model GM or Ford TPS connector per the pin-out tables below.