Efi Service Notes - Polaris MS4000 Service And Owner's Manual

EFI Service Notes

• For more convenient and accurate testing of EFI components, it is recommended dealers utilize the
Digital Wrench Diagnostic Software (dealer only), or testing may be done manually using the
™
procedures provided.
• 80% of all EFI problems are caused by wiring harness connections.
• For the purpose of troubleshooting difficult running issues, a known-good ECU from another Polaris
RANGER 700 EFI of the same model may be used without damaging system or engine components.
• Never attempt to service any fuel system component while engine is running or ignition switch is "on."
• 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.
• 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.
• Clean any connector before opening to prevent dirt from entering the system.
• Although every precaution has been taken to prevent water intrusion failure, avoid direct water or
spray contact with system components.
• Do not disconnect or reconnect the wiring harness connector to the control unit 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 positive (+) battery terminal first, followed by negative (-) cable to negative (-)
battery terminal.
• Never start the engine when the cables are loose or poorly connected to the battery terminals.
• Never disconnect battery while engine is running.
• Never use a battery boost-pack to start the engine.
• Do not charge battery with key switch "on."
• Always disconnect negative (-) battery cable lead before charging battery.
• Always unplug ECU from the wire harness before performing any welding on the unit.
ELECTRONIC FUEL INJECTION
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