Electronic Throttle Control System Operation; Etc Operation Test - Polaris Trail Blazer Service Manual

ELECTRICAL

Electronic Throttle Control System Operation

Electronic Throttle Control (ETC) Switch (Cast Aluminum Throttle Housing)
This system is used on 1999 Trail Boss, Sportsman 335, Xplorer 300, Xpress 300, Scrambler
400 (Early), and Big Boss 500 6x6 models.
The Electronic Throttle Control (ETC) system is designed to limit the engine RPM of an ATV in the event of a
mechanical problem with the throttle mechanism. The ETC switch is mounted independently of the throttle actua-
tor lever inside the throttle block assembly. This is a normally closed switch, and is held in the open position (micro
switch button depressed) by throttle cable tension. The switch is "open" in normal operation regardless of throttle
lever position. In the event of a mechanical problem in the throttle mechanism (cable tension is lost), the switch
contacts close (switch pin is released) delivering battery voltage to the Speed Limiter module via the white wire.
Battery voltage on the white wire will cause the ignition system to misfire at the "ETC Limit" listed on page 10.37.
Test the ETC switch at the terminal board or harness connector. NOTE: Adjust throttle cable freeplay (ETC
switch) and make sure throttle mechanism is functioning properly before testing the switch. Refer to Maintenance
Chapter 2 for cable adjustment procedure. Terminal board models - Disconnect White wire on terminal board
that leads from the ETC switch. Turn ignition key (and engine stop switch) "On". If voltage is present on the White
wire and throttle cable is adjusted properly, replace the ETC switch.
R/W
Normal
Fault

ETC Operation Test

Remove throttle block cover.
Place transmission in neutral and apply parking brake.
Start engine and open throttle lever slightly until engine RPM
is above the "ETC Limit" (see page 10.37 for LR module
ETC limits.
Hold throttle cable with fingers at point "A" as shown at
right and release throttle lever. If the ETC system is functioning properly engine RPM will be limited to the speci-
fied "ETC Limit" RPM. Refer to Speed Limiter System Testing on page 10.38.
99/00 ATV Update
W
F F
12/99
Electronic Throttle Control (ETC) Switch
(Cast Aluminum Throttle
Housing)
10.58
A
ETC Micro Switch
Button
Polaris Sales Inc.