ABS - Operational Characteristics

NO.: 05-08-93 Rev. A

GROUP: Brakes

DATE: Sep. 3, 1993

SUBJECT:
Antilock Brake System (ABS 6, ABS 4, Teves & Kelsey Hayes) Characteristics And Brake Pedal Feel

NOTE:
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 05-08-93 WHICH SHOULD BE REMOVED FROM YOUR FILES. THIS BULLETIN IS REVISED TO NOW INCLUDE ALL 1994 MODEL YEAR VEHICLES. ALL REVISIONS ARE HIGHLIGHTED WITH **ASTERISKS**.

MODELS:

1991 - **1994** (AA) Spirit/Acclaim/LeBaron Sedan
1994 (AB) Ram Van/Wagon
1992 - 1993 (AG) Daytona
1992 - **1994** (AJ) LeBaron Coupe/LeBaron Convertible
1993 - **1994** (AN) Dakota/Dakota Cab & Chassis
1993 - **1994** (AP) Shadow/Shadow Convertible/Sundance
**1994** (BR) Ram Pick-Up
1993 - 1994 (LH) Concorde/Intrepid/LHS/New Yorker/Vision
1992 - **1994** (XJ) Cherokee/Wagoneer
1993 - **1994** (YJ) Wrangler
1993 - **1994** (ZJ) Grand Cherokee/Grand Wagoneer

DISCUSSION:

^ Every time the ignition key is turned to the ON position, the yellow ABS lamp will come on and stay illuminated for 1-2 seconds. This is a bulb check feature to ensure the bulb is not burned out.

^ The FIRST time the vehicle is accelerated to 3-8 mph after start up, a momentary clicking of solenoid valves and running of the ABS pump motor MAY be heard. This indicates the ABS is cycling through its self-check to ensure the ABS is functioning properly. The self-check will not reoccur until the vehicle is turned OFF, started again and accelerated to 3-8 mph.

^ When the vehicle is being stopped and the brakes are in the antilock mode, the operator of the vehicle may experience: 1) The sound of the ABS pump motor running. The ABS pump may also continue to run for a short time after the end of the ABS stop. 2) The simultaneous clicking sound of the solenoid valves. 3) Brake pedal pulsations, and 4) A slight drop or fall away of brake pedal at the end of the stop. THESE CHARACTERISTICS REPRESENT NORMAL OPERATION OF THE ABS.

^ To achieve the shortest stopping distance when the brake system is in the antilock mode, maintain the force already applied to the brake pedal. DO NOT PUMP (REPEATED APPLICATION AND RELEASE) THE BRAKE PEDAL.

^ At anytime during the operation of the vehicle, the yellow antilock warning lamp may come on. This lamp indicates that a fault condition exists in the ABS and the ABS has been disabled. THE POWER ASSISTED BRAKE SYSTEM AND THE ABILITY TO STOP THE VEHICLE WILL **NOT BE AFFECTED WHEN ONLY THE YELLOW ANTILOCK WARNING LAMP IS ON. IF. AFTER CYCLING THE IGNITION SWITCH ON AND OFF, THE YELLOW ABS WARNING LIGHT STAYS ON OR COMES ON AGAIN, IT IS RECOMMENDED THAT YOU TAKE YOUR VEHICLE TO YOUR DEALER FOR SERVICE OF THE ABS AS SOON AS POSSIBLE.**

POLICY: Information Only