Dtc43 - Itp Sensor System Fault - Isuzu 4HL1 Workshop Manual

1A-134 Engine Control System

DTC43 - ITP Sensor System Fault

Circuit Description
The ITP (intake throttle position) sensor sends the
voltage signal that alters in response to the change in
throttle position to the ECM. The ECM calculates the
throttle position from this voltage signal and uses it in
intake throttle control and other control tasks.
DTC43 will be set when the output voltage from the ITP
sensor is excessively high or low.
Major Faulty Event
• Generation of black smoke
• Short power
• Poor driveability
• Extensive suction noise during acceleration or
exhaust braking
Conditions for Setting the DTC
The ITP sensor output voltage deviates from the range
between 0.1 V and 4.9 V for at least 1 second.
Action Taken When the DTC Sets
• After the DTC is set, the ECM will illuminate the
CHECK ENGINE lamp (MIL).
• Intake throttle and EGR systems are disabled.
• Fault judgment is disabled on intake throttle valve.
6 8 27 26
25
CKP CMP
Sensor Sensor
63 66 6764
69 68
ITP EGR Valve
Sensor Position
Sensor
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.
When Tech 2 has been connected to the vehicle, the
DTC can be cleared through the memory clear
operation with Tech 2.
ECM
(Engine
Control
Module)
Common
Rail
Pressure
Sensor
LNW21AMF006901-X