Engine Control Unit - Mazda 626 1989 Workshop Manual

COMPONENT DESCRIPTION
Component
A/Cs witch
Air valve
Clutch switch
E/L control unit

Engine control unit

Idle switch
Ne signal pick-up
Neutral switch
P/S pressure switch
Solenoid valve (Idle
speed control)
Test connector
Water thermo sensor
\
Function
Detects air conditioner operation; sends
signal to engine control unit
When cold, supplies bypass air into dy-
namic chamber
Detects in-gear condition; sends signal to
engine control unit
Detects that E/L is being applied; sends
signal to engine control unit
Detects signals from input sensors and
switches; controls solenoid valve (Idle
speed control)
Detects when throttle valve fully closed;
sends signal to engine control unit
Detects crank angle at 180° intervals;
sends signal to engine control unit
Detects in-gear condition; sends signal to
engine control unit
Detects P/S operation; sends signal to
engine control unit
Controls bypass air amount
For initial idle speed adjustment
Detects coolant temperature; sends
signal to engine control unit
ISC SYSTEM
Remark
Switch ON when air conditioner
operating
• Engine speed increased to shorten
warm-up period
• Thermo wax type
• Installed in BAC valve
Switch ON when clutch pedal released
**
Installed on throttle body
Installed in distributor
Switch ON when in gear
Switch ON when steering wheel turned
right or left
• Controlled by duty signal from engine
control unit
• Installed in BAC valve
• Operates id(e-up
• Green, 1-pin
• Idle speed feedback control cancelled
when connector grounded
4B
76G04C-078