Dtc24 - Accelerator Sensor System Fault - Isuzu 4HL1 Workshop Manual

1A-112 Engine Control System

DTC24 - Accelerator Sensor System Fault

Circuit Description
The AP (accelerator pedal position) sensor sends the
voltage signal that alters in response to the change in
accelerator pedal angle to the ECM. The ECM
calculates the accelerator pedal position from this
voltage signal and uses it in fuel injection control and
other control tasks.
DTC24 will be set when the signal voltage is
excessively high or low.
Major Faulty Event
• Short power
• Poor pedal response
• Poor driveability
Conditions for Setting the DTC
The AP sensor output voltage deviates from the range
between 0.1 V and 4.8 V for at least 1.5 seconds.
Action Taken When the DTC Sets
• After the DTC is set, the ECM will illuminate the
CHECK ENGINE lamp (MIL).
• The ECM controls the accelerator pedal position
according to the signals from the idle position
switch.
• EGR, warm-up, and intake throttle systems are
disabled.
110
90 84 94 108
Idle
Switch
AP
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.
ECM
(Engine
Control
Module)
• ON/OFF fault judgment is disabled on idle position
switch.
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.
LNW21AMF007501-X