Isuzu 4HL1 Workshop Manual page 91

Chart 1 (2/3)
DTC Fault
ECM Internal Fault
(CPU Error)
51
ECM Internal Fault
(CPU History Error)
ECM Internal Fault
52
(CPU Monitoring IC Fault)
Intake Throttle Valve
61
System Fault
71 Atmospheric Pressure
(VIM) Sensor Fault
81 Clutch Switch System
(VIM) Fault
82 Neutral Switch System
(VIM) Fault
CAN Communication Fault
84
(CAN Bus Error)
CAN Communication Fault
86
(CAN Timeout Error)
Common Rail Pressure
115
Sensor Fixed Output Fault
Common Rail Pressure
Fault
(First Stage in Control
System)
118
Common Rail Pressure
Fault
(Second Stage in Control
System)
Injector Power Supply
158
System Short (Common 1)
Injector Power Supply
159
System Short (Common 2)
Fuel Temperature Sensor
211
System Fault
CHECK
ENGINE Judgment start conditions
lamp status
ON
(by sub CPU)
—
ON
The starter switch is turned on for at
least 3 seconds, the ITP sensor is in
normal condition, neither #3 - 5 V
ON Power Supply Fault nor A/D
Conversion Fault is detected, and
the battery voltage stays between
16 V and 32 V.
ON
ON
ON
ON
ON
ON
ON
The battery voltage is at least 16 V,
ON the starter switch is turned on, and
the post injection is not performed.
The battery voltage is at least 16 V,
ON the starter switch is turned on, and
the post injection is not performed.
—
Judgment criteria
The sub CPU judges the CPU fail.
With the battery voltage 20 V or
—
more and the starter switch turned
off, the CPU working signals are not
detected even after the initial status
lasts for at least 0.4 second.
The post initial status lasts at least 2
seconds, the battery voltage is 22 V
or more, the starter switch is turned
—
off for at least 0.5 second, and the
CPU working signals are faulty for
0.7 second or more.
The valve drive voltage is
excessively high for at least 10
seconds.
The atmospheric pressure sensor
voltage deviates from the range
—
between 0.5 V and 4.5 V for 1
second.
On the manual transmission vehicle,
the engine is running for at least 180
seconds, the vehicle speed is at
—
least 80 km/h, and the clutch switch
is not toggled from off to on or on to
off.
The engine is running for at least
180 seconds, the vehicle speed is at
—
least 80 km/h, and the neutral switch
is toggled from on to off.
Fault occurs on communications
—
with VIM.
CAN signal is not input for 1
—
seconds.
The state where the common rail
pressure sensor is in normal
condition, there is no change in
common rail pressure sensor output
voltage, the difference between
desired and actual common rail
—
pressures is 10 MPa or more, the
actual common rail pressure is 10
MPa or more, and the pump is under
feedback control is continuously
observed 255 times during A/D
conversion in the ECM.
The state where the common rail
pressure is in normal condition and
the actual common rail pressure is
180 MPa or more is continuously
observed 5 times during A/D
conversion in the ECM. (The system
is restored when the common rail
pressure is at or below 130 MPa and
the idle position switch is turned on.)
—
The state where the common rail
pressure is in normal condition and
the actual common rail pressure is
200 MPa or more is continuously
observed 5 times during A/D
conversion in the ECM. (The system
is restored when the common rail
pressure is at or below 130 MPa and
the engine is stopped.)
The short to ground or the +B short
is detected on the common 1 drive
circuits for injectors (injectors #1 and
#3).
The short to ground or the +B short
is detected on the common 2 drive
circuits for injectors (injectors #2 and
#4).
The FT sensor output voltage
— deviates from the range between 0.1
V and 4.8 V for at least 1 second.
Engine Control System 1A-89
Fail-safe
Injectors supply pump are stopped.
Injectors supply pump are stopped.
The exhaust brake is disabled.
The exhaust brake is disabled.
Communications with VIM are
terminated and the control mode
with predetermined values will be
dominant.
Communications with ECM are
terminated and the control mode
with predetermined values will be
dominant.
The ECM controls the desired
common rail pressure to 60 MPa or
less and the desired fuel quantity to
3
50 mm /st or less.
The ECM controls the desired
common rail pressure to 60 MPa or
less and the desired fuel quantity to
3
50 mm /st or less.
Injectors and supply pump are
stopped.
The ECM stops injectors #1 and #3.
The ECM stops injectors #2 and #4.
The ECM controls the powertrain
using the set fuel temperature
(normal running phase: 40°C,
startup phase: –20°C).
—
—