Operation and maintenance manual

QSB4.5 and QSB6.7 Electronic Controlled Fuel System
Section 1 - Operating Instructions Page 1-7
Engine Shutdown
General Information
Allow the engine to idle 3 to 5 minutes before shutting it
off after a full-load operation. This allows adequate cool
down of pistons, cylinders, bearings, and turbocharger
components.
NOTE: For engines equipped with an electronic control
module (ECM) ensure the keyswitch is turned off for a
minimum of 70 seconds prior to disconnecting the
continuous (unswitched) battery power supply. If the
unswitched battery power supply is disconnected in less
than 70 seconds after the keyswitch is turned off active
fault codes and incorrect ECM information can occur.
Turn the ignition switch to the OFF position. If the engine
does not shut down, refer to Troubleshooting Symptom
(Section TS) in appropriate Operation and Maintenance
manual.
CAUTION
Failure to follow the correct shutdown procedure may
result in damage to the turbocharger and shorten the
turbocharger life.
Electronic Controlled Fuel System
General Information
The engine control system is an electronically operated
fuel control system that also provides many operator and
vehicle or equipment features.
The base functions of the control system include fueling
and timing control, limiting the engine speed operating
range between the low- and high-idle set points, and
optimizing engine performance.
The control system uses inputs from the operator and its
sensors to determine the fueling and timing required to
operate at the desired engine speed.
The engine control module (ECM) is the control center of
the system. It processes all of the inputs and sends
commands to the fuel system and vehicle and engine
control devices.
The ECM performs diagnostic tests on most of its circuits
and will activate a fault code if a problem is detected in
one of these circuits. Along with the fault code identifying
the problem, a snapshot of the engine's operating
parameters at the time of fault activation is also stored in
memory.
Some fault codes will cause a diagnostic lamp to activate
to signal the driver.