| Subject: | Normal Operating Characteristics of Cruise Control System |
| Models: | 1999-2002 Chevrolet Tracker |
This bulletin will provide information on the normal operating characteristics
of the cruise control system. Please share this information with any customers
who come into your dealership with questions regarding the cruise control
operation in their Tracker.
| • | There is a one second time delay from the moment the cruise on/off
dash switch is turned on until the moment the system will accept its first
set speed input. During this time delay, the cruise module is confirming its
home position and preparing to accept an input signal. |
| | A customer
may comment that it sometimes takes two twists of the cruise control knob
to get the system to engage. Since the first one came during the time delay
period, it was ignored by the cruise module. When confirming proper operation,
pause at least one second between turning the system on and setting the speed
input. The system should then accept the signal the first time. |
| • | Another system time delay exists from the moment a brake or cancel
input signal is received by the cruise module until the module will accept
a new input signal. Again, during this period, the module is preparing itself
to accept a new signal. This delay increases with vehicle speed since the
mechanism has a longer distance to travel when set at higher cruise speeds.
At highway speeds, the delay can be as long as 3 seconds. |
| | A customer may comment that it takes two or three twists of the cruise knob
to get it to engage when they quickly follow a brake/cancel input with a set
speed or resume signal. When confirming proper operation, pause at least three
seconds between brake/cancel inputs and the next set speed or resume input
signal. The system should then accept and engage the first time. |
Further diagnostics, including the resistance specifications to bench
test the cruise switch, can be found in SI2000.
Additionally, there are two other characteristics which are considered
normal functions related to the cruise control operation of the Tracker.
| • | When braking or canceling cruise operation, the cruise control
module immediately releases the throttle cable, allowing it to snap back to
a closed position. When this occurs without the operator's foot to catch the
released throttle, the returning pedal will hit against its stop with a thump.
This is a normal, operational characteristic and no modifications or repairs
should be attempted. |
| • | Unlike most GM cruise control systems, the Tracker's system does
not retain memory of a set cruise speed whenever the vehicle's speed reaches
40 km/h (25 mph) or less. For example, if cruising at 56 km/h
(35 mph) and a brake input is received, slowing the vehicle to 32 km/h
(20 mph), the operator cannot use the resume feature to return to cruising
at 56 km/h (35 mph). When the vehicle's speed slowed below 40 km/h
(25 mph), the set speed memory was erased. To resume cruise function,
a new set speed input must be established. |
