Speed Control - Adaptive Strategy

NO: 08-16-95 Rev. A

GROUP: Electrical

DATE: Oct. 6, 1995

SUBJECT:
Speed Control
Overshoot/Undershoot
During Initial Set Speed Selection

NOTE:
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 08-16-95, DATED APR. 14, 1995, WHICH SHOULD BE REMOVED FROM YOUR FILES. REVISIONS INCLUDE ADDITIONAL MODELS AND ADDITIONAL INFORMATION IN THE DISCUSSION. ONLY THE REVISIONS IN THE DISCUSSION ARE HIGHLIGHTED WITH **ASTERISKS**.

MODELS:

1989 - 1995 (AA) Spirit/Acclaim/LeBaron Sedan
1989 - 1996 (AB) Ram Van/Wagon
1989 - 1993 (AC) Dynasty/New Yorker/New Yorker Salon
1989 - 1993 (AD) Ram Pickup/Ramcharger
1989 - 1993 (AG) Daytona
1989 (AH) Lancer/LeBaron GTS
1989 - 1995 (AJ) LeBaron Coupe/LeBaron Convertible
1989 (AK) Aries/Reliant
1989 - 1996 (AN) Dakota/Dakota Cab & Chassis
1989 - 1994 (AP) Shadow/Shadow Convertible/Sundance
1990 - 1991 (AQ) Chrysler Maserati TC
1989 - 1995 (AS) Town & Country/Caravan/Voyager
1990 - 1993 (AY) Imperial/New Yorker Fifth Avenue
1991 - 1992 (BB) Monaco/Premier
1994 - 1996 (BR) Ram Pickup
1993 - 1995 (ES) Chrysler Voyager (European Market)
1995 - 1996 (FJ) Sebring/Avenger/Talon
1996 (GS) Chrysler Voyager (European Market)
1995 - 1996 (JA) Cirrus/Stratus/Breeze
1996 (JX) Sebring Convertible
1993 - 1996 (LH) Concorde/Intrepid/LHS/New Yorker/Vision
1991 - 1992 (MJ) Comanche
1996 (NS) Town & Country/Caravan/Voyager
1995 - 1996 (PL) Neon
1991 - 1996 (XJ) Cherokee/Wagoneer
1993 - 1996 (ZG) Grand Cherokee (European Market)
1993 - 1996 (ZJ) Grand Cherokee/Grand Wagoneer

DISCUSSION:

If the vehicle operator **repeatedly** presses and releases the SET button with their foot off of the accelerator (a "lift foot set" to begin speed control operation), the vehicle may accelerate and exceed the desired set speed by up to 5 MPH (8 km/h) and then decelerate to less than the desired set speed before finally achieving the desired set speed.

The speed control has an adaptive strategy (ability to learn) that compensates for vehicle-to-vehicle variations in speed control cable lengths. When the speed control is set with the vehicle operators foot off of the accelerator pedal, the speed control "thinks" there is excessive speed control cable slack and adapts (learns). If "lift foot sets" are continually used, the speed control overshoot/undershoot condition will develop.

To "unlearn" the overshoot/undershoot condition, the vehicle operator has to press and release the SET button while maintaining the desired set speed with the accelerator pedal (not decelerating or accelerating), and then turn the speed control switch to the OFF position **(or press the CANCEL button, if equipped) after the speed control has been engaged for 10 seconds or longer.** This procedure must be performed approximately 10-15 times to completely unlearn the overshoot/undershoot condition.

If the speed control operation procedure outlined in the Owners Manual is followed, the overshoot/undershoot condition will not occur. Please review the proper set procedure with the vehicle operator.

POLICY: Information Only