Club Car Carryall 300 2021, Руководство по техническому обслуживанию и ремонту

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25 17 690 15 Rev. -- KohlerEngines.com
EFI SYSTEM
ECU continually performs a diagnostic check of itself,
each sensor, and system performance. If a fault is
detected, ECU can turn on a Malfunction Indicator Light
(MIL) on equipment control panel, store fault code in
its fault memory, and go into a default operating mode.
Depending on signifi cance or severity of fault, normal
operation may continue. A technician can access stored
fault code using a fault code diagnosis fl ashed out
through MIL. An optional computer software diagnostic
program is also available, refer to Tools and Aids.
ECU requires a minimum of 6.0 volts to operate.
To prevent engine over-speed and possible failure, a
rev-limiting feature is programmed into ECU. If maximum
RPM limit (4400) is exceeded, ECU suppresses injection
signals, cutting off fuel fl ow. This process repeats itself in
rapid succession, limiting operation to preset maximum.
Wiring harness used in EFI system connects electrical
components, providing current and ground paths for
system to operate. All input and output signaling occurs
through two special all weather connectors that attach
and lock to ECU. Connectors are Black and Grey and
keyed diff erently to prevent being attached to ECU
incorrectly.
Condition of wiring, connectors, and terminal
connections is essential to system function and
performance. Corrosion, moisture, and poor connections
are as likely a cause of operating problems and system
errors as an actual component. Refer to Electrical
System for additional information.
EFI system is a 12 VDC negative ground system,
designed to operate down to a minimum of 6.0 volts.
If system voltage drops below this level, operation of
voltage sensitive components such as ECU, fuel pump
relay, ignition coil, and injector will be intermittent or
disrupted, causing erratic operation or hard starting.
A fully charged, 12 volt battery with a minimum of 350
cold cranking amps is important in maintaining steady
and reliable system operation. Battery condition and
state of charge should always be checked fi rst when
troubleshooting an operational problem.
Keep in mind that EFI-related problems are often caused
by wiring harness or connections. Even small amounts
of corrosion or oxidation on terminals can interfere with
milliamp currents used in system operation.
Cleaning connectors and grounds will solve problems
in many cases. In an emergency situation, simply
disconnecting and reconnecting connectors may clean
up contacts enough to restore operation, at least
temporarily.
If a fault code indicates a problem with an electrical
component, disconnect ECU connector and test for
continuity between component connector terminals and
corresponding terminals in ECU connector using an
ohmmeter. Little or no resistance should be measured,
indicating that wiring of that particular circuit is OK.
Crankshaft position sensor is essential to engine
operation; constantly monitoring rotation and speed
(RPM) of crankshaft. There are 23 consecutive teeth
cast into fl ywheel. One tooth is missing and is used to
reference crankshaft position for ECU.
When ignition is turned ON, ECU captures and records
battery voltage. During engine start (cranking) voltage
drops 2+ volts. When ECU receives voltage drop input,
it then looks for a signal from crankshaft position sensor.
During rotation, an AC voltage pulse is created within
sensor for each passing tooth. ECU calculates engine
speed from time interval between consecutive pulses.
Gap from missing tooth creates an interrupted input
signal, corresponding to specifi c crankshaft position
near BDC for cylinder. This signal serves as a reference
for control of ignition timing by ECU. Synchronization of
inductive speed pickup and crankshaft position takes
place during fi rst two revolutions each time engine is
started. Sensor must be properly connected at all times.
If sensor becomes disconnected for any reason, engine
will quit running.
Throttle position sensor (TPS) is used to indicate throttle
plate angle to ECU. Since throttle (by way of governor)
reacts to engine load, angle of throttle plate is directly
related to load on engine.
Mounted on throttle body and operated directly off end
of throttle shaft, TPS works by varying voltage signal to
ECU in direct correlation to angle of throttle plate. This
signal, along with other sensor signals, is processed by
ECU and compared to internal preprogrammed maps to
determine required fuel and ignition settings for amount
of load.
Correct position of TPS is established and set at factory.
Do not loosen TPS or alter mounting position unless
absolutely required by fault code diagnosis. If TPS
is loosened or repositioned, appropriate TPS Learn
Procedure must be performed to re-establish baseline
relationship between ECU and TPS.
Engine temperature sensor is used by system to
help determine fuel requirements for starting (a cold
engine needs more fuel than one at or near operating
temperature).
Mounted on cylinder head, it has a temperature-sensitive
resistor. Resistance changes with engine temperature,
altering voltage sent to ECU. Using a table stored in
its memory, ECU correlates voltage drop to a specifi c
temperature. Using fuel delivery maps, ECU then
knows how much fuel is required for starting at that
temperature.
Temperature/Manifold Absolute Pressure (TMAP) sensor
is an integrated sensor that checks both intake air
temperature and manifold absolute pressure.
Intake Air Temperature control is a thermally sensitive
resistor that exhibits a change in electrical resistance
with a change in its temperature. When sensor is cold,
resistance of sensor is high. As sensor warms up,
resistance drops and voltage signal increases. From
voltage signal, ECU can determine temperature of intake
air.