Vehicle Speed Control System - DaimlerChrysler LH New Yorker 1994 Electronic Service Manual

VEHICLE SPEED CONTROL SYSTEM

CHECKING FOR DIAGNOSTIC TROUBLE CODE . 5
DIAGNOSIS PROCEDURES . . . . . . . . . . . . . . . . . 2
ELECTRICAL TEST: . . . . . . . . . . . . . . . . . . . . . . . 5
ELECTRICAL TESTS AT POWERTRAIN
CONTROL MODULE . . . . . . . . . . . . . . . . . . . . . 6
ELECTRICAL TESTS AT SERVO
GENERAL INFORMATION
INOPERATIVE SYSTEM . . . . . . . . . . . . . . . . . . . . 2
ROAD TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
GENERAL INFORMATION
The speed control system is electronically controlled
and vacuum operated. The electronic control is inte-
grated into the powertrain control module, located on
the right side under the air cleaner. The controls are
located on the steering wheel and consist of two
switches. The ON and OFF, buttons are located on
the upper left side of the airbag module. The
RESUME/ACCEL and SET/COAST buttons are lo-
cated on the upper right side of the airbag module
(Fig. 1). For identification and location of the major
components (Figs. 2 and 3).
Fig. 1 Speed Control Switch
The system is designed to operate at speeds above
35 mph (50 km/h).
CONTENTS
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VEHICLE SPEED CONTROL SYSTEM
SERVO UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
SERVO VACUUM TEST . . . . . . . . . . . . . . . . . . . . 8
SPEED CONTROL RELAY TEST
SPEED CONTROL SWITCH REMOVAL . . . . . . . . 8
SPEED CONTROL SWITCH TEST
STOP LAMP/VEHICLE SPEED CONTROL SWITCH
TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
VACUUM SUPPLY TEST
Fig. 2 Speed Control System—3.5L Engine
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
TO ACTIVATE: Press the ON button. The speed
control functions are now ready for use. The system
has an AUTO-OFF feature which turns the system off
whenever the system looses power or the ignition is
turned OFF. If this happens, the ON button must be
pressed to activate the system.
TO DEACTIVATE:
• A soft tap of the brake pedal
• Normal brake application
While the system is engaged this will disengage
speed control without erasing the set speed in
memory. Pushing the OFF button or turning off the
ignition erases the set speed in memory.
TO SET SPEED: When the vehicle has reached
the desired speed push the SET/COAST button to en-
8H - 1
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