Ski-Doo FORMULA S 1997, Shop Manual

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04-1
Section 04 DESS SYSTEM
DESS SYSTEM
(Digitally Encoded Security System)
0
COMPONENT LOCATION
1. Safety lanyard switch and cap
2. Buzzer
3. MPEM
THEORY AND OPERATION
This system is a deterrent against theft. Dealer
programmed, the tether cord provided with the
snowmobile is the only one that allows engine to
turn more than 2500 RPM. If a wrong tether cord
is installed the engine can not reach engagement
speed required to move vehicle.
The snowmobile micro-processor (MPEM) can be
programmed to allow the use up to 8 tether cords.
After engine is started 2 beeps confirm that the
micro-processor has recognized the tether cord.
The vehicle can be normally driven.
A beep per 3 seconds and DESS pilot lamp blink-
ing as same rate mean that a bad connection has
been detected. Vehicle can not be driven.
To check for bad connection, remove tether cord
make sure it is free of dirt or snow. Reinstall teth-
er cord and restart engine. If a beep per 3 seconds
still occurs verify tether cord switch.
A continuous beep and DESS pilot lamp blinking
rapidly mean that a wrong tether cord is installed.
Vehicle can not be driven.
Check that you have both good vehicle and tether
cord.
Multi-Purpose Electronic Module
(MPEM)
NOTE: The module must be programmed in order
to accept a tether cord.
This module cuts off the ignition at 2500 RPM in
antitheft mode (wrong tether cord) or in case of a
bad connection.
The module activates the indicator light and the
alarm (depending on the antitheft mode).
It also activates the back-up alarm when required.
MPEM
1. PTO high-tension coil; 3-05 housing
2. CENTER high-tension coil;3-04 housing
3. MAG high-tension coil; 3-03 housing
4. Trigger coil; 2-03 housing
5. Positive supply; 2-03 housing
6. Ground, warning device, indicator light, DPM signal, engine shut-
off; 3-06 housing
7. DESS switch
8. Load breaker
DESS Indicator Light
This indicator light comes on when the DESS sys-
tem is activated.
The indicator light blinks at the rate of once every
3 seconds to indicate a bad connection of the
tether cord.
The indicator light blinks rapidly to indicate a
wrong tether cord.
A06E2MA
2
1
3
A00E4YA
1
2
3
4
6
5
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8
PARTS