Polaris 2009 IQ Turbo Switchback, Owner'S Manual

Page: 39 / 161

36
FEATURES
Knock Sensor
A knock sensor monitors the engine and responds to detonation by auto-
matically reducing the engine timing and adding fuel. This results in
decreased engine RPM and performance.
Engine performance will be reduced if fuel with a lower octane than 91
is used. See fuel recommendations on page 79.
Effect
The knock sensor system prevents damage to the engine from detona-
tion while developing the maximum power of the engine safely. If the
system senses detonation beyond a preset limit, it retards ignition timing
and adds fuel to reduce the detonation and prevent engine damage.
When the detonation returns to a permissible level, the system will
return spark and fuel to normal, allowing the engine to run at rated
power levels.
Fail-Safe
The knock sensor includes a sensor fail-safe system to prevent the
engine from damage if the sensor fails, becomes disconnected or is
unable to detect detonation. The rider will experience a loss in power.
The sensor must be reconnected or repaired to regain full power.
The check engine light will illuminate if the sensor fails or becomes dis-
connected.