Dtc61 - Intake Throttle Valve System Fault - Isuzu 4HL1 Workshop Manual

1A-154 Engine Control System

DTC61 - Intake Throttle Valve System Fault

Circuit Description
The intake throttle valve is operated by the DC motor.
The DC motor operates the intake throttle valve by
changing the drive voltage (duty). The valve is closed
when the drive voltage is increased while opened when
the voltage is decreased. The ECM calculates the
desired intake throttle valve position based on the
vehicle running condition and controls the DC motor
accordingly.
DTC61 will be set when the difference between desired
and actual intake throttle valve positions is large or the
drive voltage is excessively high.
Major Faulty Event
• Generation of black smoke
• Short power
• Poor driveability
Conditions for Setting the DTC
The state where the ITP sensor is in normal condition
and the valve drive voltage is excessively high lasts for
at least 10 seconds.
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.
• The intake throttle valve DC motor is deenergized.
16 58 59
35
M M
M-
M- M+
M+
Intake
EGR
Throttle DC Motor
DC Motor
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
2. Turn on the idle position switch for not less than 1
3. Turn off the idle position switch for not less than 1
4. Turn on the idle position switch for not less than 1
5. Turn off the idle position switch for not less than 1
6. After the above operations are properly completed,
7. Turn off the starter switch. Wait for 5 seconds and
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)
second but not more than 3 seconds. (Press the
accelerator pedal.)
second but not more than 3 seconds. (Release the
accelerator pedal.)
second but not more than 3 seconds. (Press the
accelerator pedal.)
second but not more than 3 seconds. (Release the
accelerator pedal.)
second but not more than 3 seconds. (Press the
accelerator pedal.)
the CHECK ENGINE lamp (MIL) illuminates for 3
seconds to report the memory is cleared.
turn on the starter switch again.
LNW21AMF007301-X