Dtc271 - Cylinder 1 (Injector Drive System) Fault - Isuzu 4HL1 Workshop Manual

DTC271 - Cylinder 1 (Injector Drive System) Fault

Circuit Description
The injector drive circuit is a low-voltage system and
drives injectors. The ECM calculates the optimum fuel
injection timing using the data acquired from sensors
and energizes injector coils (TWV). The ECM also
controls the fuel injection timing based on the injector
drive timing and the fuel injection quantity based on the
coil energize time.
DTC271 will be set when fault(s) occur on the cylinder
1 injector drive system.
Major Faulty Event
• Short power
• Poor driveability
Conditions for Setting the DTC
Open wiring is detected on the circuit between injector
#1 and ECM injector #1 pin, and Cylinder 4 (Injector #3
drive circuit) Fault (DTC274) is not detected.
Action Taken When the DTC Sets
• After the DTC is set, the ECM will illuminate the
CHECK ENGINE lamp (MIL).
• Fault judgment is disabled on supply pump
system.
• Only main injection is enabled.
• The calibrated
quantity becomes 0 mm
23 5 4
24
Cylinder 2 Cylinder 3
cylinder-to-cylinder injection
3
/st.
2 1
42 43
Cylinder 4 Cylinder 1
• Fuel injection at cylinder 1 (injector #1) is
terminated.
Conditions for Clearing MIL/DTC
When the system fails and the DTC is stored to the
ECM, even repairing the faulty portion will not clear the
DTC from the memory. To clear the DTC, conduct the
following steps.
1. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
2. Turn on the idle position switch for not less than 1
second but not more than 3 seconds. (Release the
accelerator pedal.)
3. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
4. Turn on the idle position switch for not less than 1
second but not more than 3 seconds. (Release the
accelerator pedal.)
5. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
6. After the above operations are properly completed,
the CHECK ENGINE lamp (MIL) illuminates for 3
seconds to report the memory is cleared.
7. Turn off the starter switch. Wait for 5 seconds and
turn on the starter switch again.
Engine Control System 1A-219
ECM
(Engine
Control
Module
LNW21AMF007001-X