Ecu Service; Ecu Removal / Replacement - Polaris Sportsman 850 Service Manual

FUEL SYSTEM
RPM Limit:
Hard Limit - Fuel injector suppression occurs
• All Gears: 7600 RPM
Soft Limit - Spark timing suppression occurs
• All Gears: 7250 RPM

ECU SERVICE

Never attempt to disassemble the ECU. It is sealed to
prevent damage to internal components. Warranty is void
if the case is opened or tampered with in any way.
All operating and control functions within the ECU are
pre-set. No internal servicing or readjustment may be
performed. If a problem is encountered, and you
determine the ECU to be faulty, the assembly needs to
be replaced. Do not replace the ECU under warranty
without factory authorization. Coverage does not apply
without authorization from Polaris Technical Service.
For the purpose of troubleshooting, a known-good ECU
from another Polaris vehicle of the same model and year
may be used, but ensure that you do not put an ECU
from a machine equipped with EPS into a non-EPS
model. This will force update the cluster, and it will be
permanently set it as an EPS cluster, leaving the EPS
warning light on with no way of turning it off.

ECU REMOVAL / REPLACEMENT

1. Remove the seat and upper side panels from the
vehicle.
2. Remove the (4) push rivets from each front mud
guard and remove the mud guards from the vehicle.
3. Remove the front rack or storage box assembly.
4. Disconnect the negative battery cable.
Be sure to cover fuel tank inlet with a shop towel prior to
front cab removal.
5. Remove the front cab assembly.
6. Remove the rubber strap retaining the ECU to the
airbox.
7. Disconnect the wire harness from the ECU by pulling
the black slider out away from the ECU while pulling
down on the connector. Once the slider is fully
extended, pull the connector from the ECU, using
care not to damage the connector or locking
mechanism.
4.22
NOTE
8. Carefully remove the ECU from the vehicle.
9. To install, reverse the previous steps. DO NOT apply
dielectric grease to the connector, as it is a sealed
connector.
If replacing the ECU, you must reflash the new ECU
with the correct calibration upon installation and prior to
attempting to start the vehicle.
NOTE