Efi Service Notes - Polaris A12MH46AX Service Manual

500 EFI FUEL SYSTEM

EFI SERVICE NOTES

General Service Information
• For more convenient and accurate testing of EFI components, it is recommended dealers utilize the Polaris Diagnostic
Software (dealer only), or limited testing may be done manually using the procedures provided.
• 80% of all EFI problems are caused by wiring harness connections. Follow a common sense approach when
diagnosing a potential EFI issue:
1. Disconnect the harness at the suspected sensor connector.
2. Inspect the connector ends for damage or contamination. If damaged, repair; if contaminated, clean. Reconnect and
check function.
3. If the problem persists, perform a sensor bench test according to the specific sensor requirements.
4. If the sensor bench tests pass, disconnect the connector at the ECU and perform a continuity check between the sensor
connector and the appropriate pin at the ECU connector (all connections for that sensor). Wiring resistance should be less
than five (5) ohms.
5. If the resistance is high (or open), a wiring harness inspection is dictated (including a thorough inspection of the ECU
connector for contamination or damage).
6. If the sensor passes and the wiring passes inspection, and reconnecting the ECU does not resolve the issue, then at that
point a known-good ECU (from another 500 EFI ATV) could be connected and tested for problem resolution.
• For the purpose of troubleshooting difficult running issues, a known-good ECU from a same-model Polaris 500 ATV EFI
system may be used without damaging system or engine components.
• Do not use dielectric grease on sealed connectors (connectors with a rubber grommet), as it may displace the rubber seal
and allow contaminants to enter the connector.
• Never attempt to service any fuel system component while engine is running or ignition switch is turned to "on".
• USE CARE when removing or installing the ECU connector, as well as all other harness connections on the ATV.
Dirt, even in small quantities, can cause significant problems. Clean connectors thoroughly before opening to prevent dirt
from entering. Properly connect and disconnect the ECU harness to minimize damage to the connector pins and locking
mechanism.
• Do not use compressed air if the EFI 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.
• 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 quick-start battery charger to start the engine.
•
Always unplug ECU from the wire harness before performing any welding on the ATV.
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9923412 - 2012 Sportsman 400/500 and EFI Tractor Service Manual
© Copyright 2011 Polaris Sales Inc.