Dtc28 - Pto Accelerator Sensor System Fault - Isuzu 4HL1 Workshop Manual

1A-120 Engine Control System

DTC28 - PTO Accelerator Sensor System Fault

0.5
R/B
PTO Sensor
Circuit Description
The PTO accelerator sensor sends the voltage signal
that alters in response to the change in PTO control
lever angle to the VIM. The VIM calculates the PTO
control lever angle from this voltage signal and sends it
to the ECM through CAN communications. Then, the
ECM uses the voltage signal in fuel injection control
during PTO.
DTC28 will be set when the PTO accelerator sensor
output signal is excessively high.
Major Faulty Event
• Poor driveability
Conditions for Setting the DTC
The PTO accelerator sensor output signal exceeds 4.9
V for 1 second.
Action Taken When the DTC Sets
• Even after the DTC is set, the ECM will not
illuminate the CHECK ENGINE lamp (MIL).
• The ECM controls the powertrain using the set
PTO accelerator position (0 %).
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
34 31 71
0.5 0.5
Y Y/BR
30
0.5
Y/G
Idling
Control
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.
VIM
(Vehicle
Interface
Module)
VS Sensor
LNW21AMF007801-X