Ecm Power Supply And Grounding System Circuit Check - Isuzu 4HL1 Workshop Manual

1A-56 Engine Control System
Step
Re-observe the CHECK ENGINE lamp for
operation.
1. Certainly connect connectors.
2. Short DLC pins 4 and 6.
10
3. Starter switch "ON", and observe the
CHECK ENGINE lamp.
Does the CHECK ENGINE lamp blink?

ECM Power Supply and Grounding System Circuit Check

Circuit Description
The power is supplied to the ECM from the battery via
the main relay. After the ECM recognizes the ON signal
from the starter switch and turns on the main relay, the
power is supplied to the ECM.
Action
SBF
100A
Battery
0.5B
Main
Relay
118 117 116 115 114
Value(s)
—
SBF
50A
3W/L
IG
SBF
(ST)
50A
SBF SBF
#22
30A 60A
10A
Glow
Relay
Glow
Relay
113 109
95 87
121 120 119
Yes
The repair is
complete Go to Step 1
IG
(ON)
#19
15A
ECM
(Engine
Control
Module)
No
LNW21ALF005001-X