Isuzu 4HL1, Workshop Manual

Page: 84 / 267

1A-82 Engine Control System
50/63 Exhaust Brake
Valve ON/OFF This parameter refers to the
status of the signals output from
the VIM to the exhaust brake
solenoid valve. After necessary
conditions such as engine speed,
QWS, automatic transmission,
ASR, and exhaust brake switch
are met, the ECM turns on the
solenoid valve. When the display is fixed, the
exhaust brake valve, circuit, VIM,
or ECM may be faulty.
51/63 Diagnostic
Switch ON/OFF This parameter refers to the
status of the signals input from
the diagnostic switch to the ECM.
It appears on the display after
DLC (data link connector) pins
are jumpered. When the display is fixed, the
DLC (data link connector), circuit,
or ECM may be faulty.
52/63 Diagnostic
Switch (VIM) ON/OFF This parameter refers to the
status of the signals input from
the diagnostic switch to the VIM.
It appears on the display after
DLC (data link connector) pins
are jumpered. When the display is fixed, the
DLC (data link connector), circuit,
VIM, or ECM may be faulty.
53/63 PTO Switch ON/OFF This parameter refers to the
status of the signals input from
the PTO switch to the VIM. It
appears on the display after the
PTO switch in the cab is pressed. When the display is fixed, the
PTO switch, circuit, VIM, or ECM
may be faulty.
54/63 A/C Switch (Air
Conditioning) ON/OFF This parameter refers to the
status of the signals input from
the A/C switch to the VIM. It
appears on the display after the
A/C switch in the cab is pressed. When the display is fixed, the A/C
switch, circuit, VIM, or ECM may
be faulty.
55/63 Exhaust Brake
(AT) Cutoff
Switch ON/OFF This parameter refers to the
status of the exhaust bake cut
signals input from the AT
controller to the VIM. It appears
on the display after the signals
are input. When the display is fixed,
communications with AT
controller, ATcontrol system,
VIM, ECM, or ABS/ASR control
unit may be faulty.
56/63 Exhaust Brake
(ASR) Cutoff
Switch ON/OFF This parameter refers to the
status of the exhaust bake cut
signals input from the ABS/ASR
controller to the VIM. It appears
on the display after the signals
are input. When the display is fixed,
communications with ABS/ASR
control unit, ABS/ASR system,
VIM, ECM, or ABS/ASR control
unit may be faulty.
57/63 Glow Time Relay ON/OFF This parameter refers to the
status of the signals output from
the ECM to the glow relay. It
appears on the display after
necessary conditions such as
engine coolant temperature,
engine speed, EGR, and QWS
switch are met. When the display is fixed, the
relay, circuit, or ECM may be
faulty.
Item
Tech 2 Data
Display
Units
displayed
Description How to use parameters