3.0 Glossary

BOP ……... Buick, Olds, Pontiac, Cadillac
DIS ……... GM Distributorless Ignition used on Buick V6 (one coil for every two spark plugs)
ECU ……... Engine Control Unit
HEI ……... GM High Energy Ignition
IPU ……... Inductive Pickup Ignition — Racing crank trigger ignitions and magnetic pickup distributors
NC ……... Normally Closed
NO ……... Normally Open
PWM ……... Pulse Width Modulated — Varying the duty cycle of a solenoid to control the volume or pressure in a hydraulic circuit
SCU ……... Speedometer Control Unit — (TCI Part# 377300) uses the VSS signal to drive a standard style speedometer cable.
TCC ……... Torque Converter Clutch — controls the apply and release of the torque converter lock-up
TCU ……... Transmission Control Unit
TISS ……... Transmission Input Speed Sensor — magnetic pickup monitoring the forward clutch drum on a 4L80E/4L85E
TOSS ……... Transmission Output Speed Sensor — magnetic pickup monitoring output shaft speed
TPS ……... Throttle Position Sensor — relays throttle opening/closing to ECU and/or TCU
VSS ……... Vehicle Speed Sensor
WOT ……... Wide Open Throttle