ABS Module

Remove and replace the ABS control module (CAB) located in the engine compartment. This procedure involves disconnecting the battery, removing the module mounting hardware, and performing a system bleed and calibration.

Warnings

Tools required

Parts

• ABS Control Module (CAB - Controller Anti-lock Brake) × 1 — Mopar 68028327AB or equivalent
• Dielectric grease × 1 — Use OEM specification

Fluids

• DOT 3 brake fluid — 1 qt

Preparation

1. Park vehicle on level ground and set parking brake
2. Turn ignition off and remove key
3. Open hood and secure with prop rod
4. Disconnect negative battery cable, then positive battery cable, and wait at least 2 minutes
5. Locate the ABS module assembly mounted on the driver side frame rail near the brake master cylinder
6. Have a catch container ready for any brake fluid that may drip from lines
7. Take photos of brake line routing and electrical connector orientation for reference during reassembly

Procedure

1. 1

   Remove ABS module electrical connector
   Locate the large electrical connector on the ABS module. Press the red or gray locking tab and carefully pull the connector straight away from the module. Do not pull on wires. If connector is stuck, use electrical contact cleaner and gently wiggle while pulling.
2. 2

   Mark and remove brake lines
   Using a permanent marker or masking tape, mark each brake line and its corresponding port on the ABS module for correct reinstallation. There are multiple brake lines connected to the module (verify exact count on your specific module, typically 4 to 6 lines). Using an 11mm line wrench, loosen each brake line fitting approximately 1-2 turns. Brake fluid will begin to seep out. Place shop towels underneath to catch drips.
3. 3

   Remove brake lines completely
   Once all fittings are loosened, fully unthread each brake line from the module. Cap or plug each line immediately to minimize fluid loss and prevent contamination. Allow fluid to drain from module ports into catch container. Keep track of which line came from which port.
4. 4

   Remove module mounting fasteners
   Locate the module mounting bracket secured to the frame rail. Remove the mounting bolts (typically two or three 10mm or 8mm bolts depending on model year production). Support the module with one hand while removing the final bolt as the assembly is heavy (approximately 8-10 lbs when full of fluid).
5. 5

   Remove ABS module from vehicle
   Carefully lift the ABS module assembly away from the mounting bracket. Tilt as needed to clear surrounding components. Keep module upright to minimize fluid spillage. Place old module on shop towels in a safe location.
6. 6

   Prepare new ABS module
   Remove new ABS module from packaging. Inspect all brake line ports for protective caps or plugs and remove them just before installation. Compare new module to old module to verify correct replacement part. Check that electrical connector pins are straight and undamaged.
7. 7

   Install new ABS module
   Position new ABS module into mounting bracket on frame rail. Align mounting holes and install mounting bolts finger-tight. Do not fully tighten yet to allow for slight adjustment when reconnecting brake lines.
8. 8

   Reconnect brake lines
   Using your reference marks from Step 2, thread each brake line into its correct port on the new module. Start all fittings by hand to prevent cross-threading. Once all lines are hand-started, tighten each fitting with the line wrench to the factory torque specification (typically approximately 15-20 ft-lbs for brake line fittings). Do not overtighten as brake line fittings can strip easily.
9. 9

   Secure module mounting
   With brake lines connected, ensure module is properly seated in mounting bracket. Tighten mounting bolts securely. Tighten mounting bolts to the factory torque specification for the fastener size (approximately 7 ft-lbs for M6 or 17 ft-lbs for M8 bracket bolts — verify in service manual).
10. 10

    Reconnect electrical connector
    Clean electrical connector on vehicle harness with electrical contact cleaner if needed. Apply small amount of dielectric grease to connector pins on new module. Align connector and push firmly until locking tab clicks into place. Tug gently to verify secure connection.
11. 11

    Refill brake fluid reservoir
    Locate brake fluid reservoir at master cylinder. Fill to MAX line with fresh brake fluid meeting the specification stamped on the master cylinder reservoir cap (typically DOT 3 for this platform). Keep reservoir at least 3/4 full throughout entire bleeding procedure.
12. 12

    Reconnect battery
    Reconnect positive battery cable first, then negative battery cable. Ensure terminals are clean and connections are tight.
13. 13

    Perform conventional brake bleeding
    Bleed brakes in the factory-specified sequence for this vehicle (verify in service manual; commonly right rear, left rear, right front, left front). At each wheel, attach clear tubing to bleeder screw, have assistant pump brake pedal 3-4 times and hold, open bleeder until fluid flows with no air bubbles, close bleeder before pedal reaches floor. Repeat until no air bubbles appear. Check and refill reservoir frequently.
14. 14

    Perform ABS system bleeding with scan tool
    Connect scan tool capable of ABS bleeding function (such as Autel, Snap-on, or dealer tool). Turn ignition to ON position (do not start engine). Navigate to ABS bleeding function. Follow scan tool prompts to cycle ABS solenoids and pump. This will purge air from HCU internal passages. Monitor brake fluid level continuously and refill as needed. Perform scan tool bleeding cycle at least twice.
15. 15

    Final brake bleeding
    After scan tool bleeding, repeat conventional brake bleeding procedure from Step 13 at all four wheels to remove any remaining air. Ensure firm, consistent brake pedal before proceeding. Top off brake fluid reservoir to MAX line.

Reassembly

1. Verify all brake line fittings are tight with no visible leaks
2. Verify electrical connector is fully seated and locked
3. Verify brake fluid reservoir is at MAX line
4. Clear any DTCs (diagnostic trouble codes) using scan tool
5. Check that ABS warning light on dash follows normal sequence: illuminates with key ON, extinguishes after engine start

Verification

• Start engine and verify ABS warning light extinguishes within 3-5 seconds
• With engine running, press brake pedal firmly - it should feel solid with no sponginess or excessive travel
• Perform a test drive in a safe area at low speed (5-10 mph) and verify normal brake operation
• Perform controlled ABS activation test: on dry pavement in a safe area, accelerate to 15-20 mph and brake firmly while turning slightly to trigger ABS - you should feel pulsation and hear ABS pump motor activate
• After test drive, recheck all brake line fittings for leaks with engine off
• Verify brake fluid level has not dropped - if level is low, air remains in system and additional bleeding is required
• Use scan tool to verify no ABS fault codes are present
• If any warning lights remain illuminated or brake pedal feels soft, DO NOT DRIVE VEHICLE - repeat bleeding procedure or seek professional service

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