Isuzu 4HL1, Workshop Manual

Page: 93 / 267

Engine Control System 1A-91
Chart 2 (1/2)
DTC Fault Major faulty event Parts to be inspected Applicable Tech 2 parameter
14 CMP Sensor System Fault Poor startability
Wire harnesses and connectors (G sensor
system), G sensor, ECM
Engine Speed
15 CKP Sensor System Fault
Poor startability
Poor driveability Wire harnesses and connectors (NE sensor
system), NE sensor, ECM
Engine Speed
18
(VIM)
Starter degradation
(MT vehicles)
Poor startability Starter Engine Start Counts
22 IAT Sensor System Fault Poor driveability
Wire harnesses and connectors (IAT sensor
system), IAT sensor, ECM Intake Air Temperature, IAT
Sensor
23 ECT Sensor System Fault
Poor startability under cold
weather conditions
Poor driveability
Prolonged warm-up time
Wire harnesses and connectors (ECT sensor
system), ECT sensor, ECM Coolant Temperature, ECT
Sensor
24 Accelerator Sensor System Fault
Short power
Poor pedal response
Poor driveability
Wire harnesses and connectors (AP sensor
system), AP sensor, ECM Final Accelerator Opening,
Acceleraator Sensor
25
(VIM)
Vehicle Speed Sensor System
Fault Improper speedometer indication
Poor driveability Wire harnesses and connectors (VS sensor
system), VS sensor, ECM
Vehicle Speed
28
(VIM)
PTO Accelerator Sensor System
Fault
Poor driveability
Wire harnesses and connectors (PTO accelerator
sensor system), PTO accelerator sensor, ECM PTO Accelerator Opening, PTO
Accelerator Sensor
31
(VIM)
Idle Up Volume System Fault Poor driveability
Wire harnesses and connectors (idle up volume
system), idle up volume, ECM
Engine Speed, Idle Up Volume
33
(VIM)
VIM Internal Fault
(EEPROM Write Error)
— VIM Engine Start Counts
34
ECM Internal Fault
(Charge Circuit Fault)
Generation of black smoke
Short power
Poor driveability
ECM System Voltage
35
(VIM)
VIM Internal Fault
(A/D Conversion Fault)
Generation of white/black smoke
Inactive idle up volume system
Inactive PTO accelerator sensor
system
VIM —
43 ITP Sensor System Fault
Generation of black smoke
Short power
Poor driveability
Extensive suction noise during
acceleration or exhaust braking
Wire harnesses and connectors (ITP sensor
system), ITP accelerator sensor, ECM
Actual Intake Throttle Position,
Desired Intake Throttle Position,
Intake Throttle Valve, Intake
Throttle Duty Ratio
44
EGR Valve Position Sensor
System Fault
Generation of black smoke
Short power
Poor driveability Wire harnesses and connectors (EGR valve
position sensor system), EGR valve position
sensor, ECM
EGR Valve Position Sensor, EGR
Duty Cycle
45 EGR Valve System Fault
Generation of black smoke
Short power
Poor driveability Wire harnesses and connectors (EGR valve and
EGR DC motor system), EGR valve, main relay,
EGR DC motor, ECM
EGR Valve Position Sensor, EGR
Duty Cycle
46
(VIM)
Exhaust Brake System Fault
(ON circuit open wiring)
Inactive exhaust brake system,
PTO and QWS
Inactive ABS/ASR Wire harnesses and connectors (exhaust brake
solenoid valve system), exhaust brake solenoid
valve, ECM
Exhaust Brake Valve 1
Exhaust Brake System Fault
(OFF circuit open wiring)
51
ECM Internal Fault (CPU Error)
Engine stop ECM DTC
ECM Internal Fault
(CPU History Error)
52
ECM Internal Fault
(Sub CPU Error)
Poor driveability ECM All data list
61
Intake Throttle Valve System
Fault
Generation of black smoke
Short power
Poor driveability Wire harnesses and connectors (intake throttle
valve system), intake throttle valve, main relay,
intake throttle DC motor, ECM
Actual Intake Throttle Position,
Desired Intake Throttle Position,
Intake Throttle Valve, Intake
Throttle Duty Ratio
71
(VIM)
Barometric Pressure Sensor
Fault
Generation of black smoke VIM
Barometric Pressure, Barometric
Pressure Sensor
81
(VIM)
Clutch Switch System Fault
Inactive exhaust brake, QWS, and
PTO Wire harnesses and connectors (clutch switch
system), clutch switch, ECM
Clutch Switch
82
(VIM)
Neutral Switch System Fault
Generation of black smoke
Poor driveability
Inactive exhaust brake and QWS
Wire harnesses and connectors (neutral switch
system), neutral switch, ECM
Neutral Switch
84
CAN Communication Fault
(CAN Bus Error)
Poor driveability
Terminated VIM control
(e.g., tachometer or PTO)
ECM Vehicle Speed
86
CAN Communication Fault
(CAN Timeout Error)
Poor driveability
Terminated VIM control
(e.g., tachometer or PTO)
VIM Vehicle Speed
115
Common Rail Pressure Sensor
Fixed Output Fault
Poor startability
Generation of while/black smoke
Short power
Poor driveability
Wire harnesses and connectors (common rail
pressure sensor system), common rail pressure
sensor, ECM
Actual Rail Pressure, Common
Rail Pressure Sensor
118
Common Rail Pressure Fault
(First Stage in Control System)
Poor startability
Generation of while/black smoke
Short power
Poor driveability
Wire harnesses and connectors (common rail
pressure sensor system), common rail pressure
sensor, SCV, flow damper, fuel pipe, ECM
Actual Rail Pressure, SCV Duty
Ratio, SCV Current
Common Rail Pressure Fault
(Second Stage in Control
System)
158
Injector Power Supply System
Short (Common 1) Short power
Poor driveability Wire harnesses and connectors (injector #1/3 to
ECM common 1 pin), injectors #1 and #3, ECM
Cylinder 1/4 Compensation
159
Injector Power Supply System
Short (Common 2) Short power
Poor driveability Wire harnesses and connectors (injector #2/4 to
ECM common 2 pin), injectors #2 and #4, ECM
Cylinder 2/3 Compensation