Isuzu 4HL1, Workshop Manual

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1A-4 Engine Control System
Engine Control System
The engine control system comprehends vehicle status
and driver’s intention based on the data acquired from
sensors and switches to adapt the engine to changing
situation so that the vehicle will achieve optimal running
condition. The heart of the engine control system is
ECM and this device provides direct control tasks for
the engine system, including fuel injection control,
intake throttle control, EGR control, and QWS control.
The ECM also governs vehicle system control
strategies such as exhaust brake control and idle stop
control via VIM. In addition, the ECM communicates
with other key systems, including ABS/ASR system
and clutch free system, via VIM.
LNW21ALF004601-X
Switch
A/C switch
Relay/Lamp
Starter cut relay
Glow relay
Check engine lamp
Tachometer
TCM
ABS/ASR ECU
ISS ECU
Vehicle functions
Atomospheric
pressure sensor
VIM
(Vehicle Interface Module)
ECM
(Engine Control Module)
Relay
ECO Relay,
Exhaust Brake
Idle
Idle Up Volume
Others
Freezer Switch
Clean Starting Memory
QWS Switch
Lamp
Exhaust Brake Lamp
Glow Lamp
Brake
Stop Lamp Relay
Exhaust Brake Lamp
Power Take OFF (PTO)
Quick Warm Up System
PTO Switch (ACTIVE HIGH)
PTO Switch (ACTIVE LOW)
PTO Accelerator Sensor
Transmission
Clutch Switch
Neutral Switch (MT)
Parking
/Neutral (AT)
Switch
Vehicle Speed Sensor
Accelerator
AP sensor
Idle position switch
CAN
Main relay
IAT sensor
Exhaust brake
solenoid valve
B
Starter
Outer diagnostic unit
Battery
Ignition switch
Starter switch
Diagnostic switch
Common rail
pressure sensor
SCV
FT sensor
Injector
EGR valve drive
EGR cooler
Exhaust
pipe
Supply
pump
EGR valve position sensor
CMP sensor
ITP sensor
Intake throttle drive
ECT
Common rail
CKP