Isuzu 4HL1 Workshop Manual page 84

1A-82 Engine Control System
Tech 2 Data
Item
Display
50/63 Exhaust Brake
Valve
51/63 Diagnostic
Switch
52/63 Diagnostic
Switch (VIM)
53/63 PTO Switch
54/63 A/C Switch (Air
Conditioning)
55/63 Exhaust Brake
(AT) Cutoff
Switch
56/63 Exhaust Brake
(ASR) Cutoff
Switch
57/63 Glow Time Relay
Units
displayed
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.
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.
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.
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.
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.
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.
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.
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.
Description How to use parameters
When the display is fixed, the
exhaust brake valve, circuit, VIM,
or ECM may be faulty.
When the display is fixed, the
DLC (data link connector), circuit,
or ECM may be faulty.
When the display is fixed, the
DLC (data link connector), circuit,
VIM, or ECM may be faulty.
When the display is fixed, the
PTO switch, circuit, VIM, or ECM
may be faulty.
When the display is fixed, the A/C
switch, circuit, VIM, or ECM may
be faulty.
When the display is fixed,
communications with AT
controller, ATcontrol system,
VIM, ECM, or ABS/ASR control
unit may be faulty.
When the display is fixed,
communications with ABS/ASR
control unit, ABS/ASR system,
VIM, ECM, or ABS/ASR control
unit may be faulty.
When the display is fixed, the
relay, circuit, or ECM may be
faulty.