Important Service Notes; Electrical Components; Electronic Control Unit (Ecu) - Kohler COMMAND CV17-745 Service Manual

Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
Section 5B
EFI Fuel System
During certain operating periods such as cold starts,
warm up, acceleration, etc., an air/fuel ratio richer than
14.7:1 is required and the system operates in an "open
loop" mode. In "open loop" operation the oxygen
sensor output is not used, and the controlling
adjustments are based on the primary sensor signals
and programmed maps only. The system operates
"open loop" whenever the three conditions for closed
loop operation (above) are not being met.

Important Service Notes!

• Cleanliness is essential and must be
maintained at all times when servicing or
working on the EFI system. Dirt, even in small
quantities, can cause significant problems.
• Clean any joint or fitting with parts cleaning
solvent before opening to prevent dirt from
entering the system.
• Always depressurize the fuel system through
the test valve in the fuel rail before
disconnecting or servicing any fuel system
components. See fuel warning on page 5B.2.
• Never attempt to service any fuel system
component while the engine is running or the
ignition switch is "on".
• Do not use compressed air if the system is
open. Cover any parts removed and wrap any
open joints with plastic if they will remain open
for any length of time. New parts should be
removed from their protective packaging just
prior to installation.
• Avoid direct water or spray contact with system
components.
• Do not disconnect or reconnect the main ECU
wiring harness connector or any individual
components with the ignition ''on.'' This can
send a damaging voltage spike through the
ECU.
• Do not allow the battery cables to touch
opposing terminals. When connecting battery
cables attach the positive (+) cable to the
positive (+) battery terminal first, followed by the
negative (-) cable to the negative (-) battery
terminal.
5B.4
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Electrical Components

Electronic Control Unit (ECU)

Figure 5B-1. "24 Pin" (MSE 1.0) Plastic-Cased ECU.
Figure 5B-2. "32 Pin" (MSE 1.1) Plastic-Cased ECU.
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Never start the engine when the cables are loose
or poorly connected to the battery terminals.
Never disconnect the battery while the engine is
running.
Never use a quick battery charger to start the
engine.
Do not charge the battery with the key switch
''on.''
Always disconnect the negative (-) battery cable
before charging the battery, and also unplug the
harness from the ECU before performing any
welding on the equipment.