Remove and replace the ABS modulator assembly, including bleeding the brake system and performing system relearn procedures.

Warnings

Tools required

Parts

• ABS modulator assembly × 1 — Use OEM Honda part number for 1.5T Civic
• Brake line sealing washers × 4 — Replace all 4 brake line washers

Fluids

• DOT 3 Brake Fluid — 1.5 qt

Preparation

1. Park vehicle on level ground and apply parking brake
2. Turn ignition off and remove key
3. Open hood and disconnect negative battery terminal (10mm wrench). Wait 3 minutes for airbag system capacitors to discharge
4. Remove engine cover if equipped by pulling upward on retaining clips
5. Locate ABS modulator assembly on driver side firewall area, below brake master cylinder
6. Using turkey baster or syringe, remove as much brake fluid as possible from master cylinder reservoir to minimize spillage
7. Place drain pan under ABS module area to catch brake fluid
8. Have at least 1 quart of fresh DOT 3 brake fluid ready from sealed container

Procedure

1. 1

   Remove electrical connector
   Locate the large multi-pin electrical connector on the ABS module. Press the locking tab and carefully pull the connector straight off. Do not pull on wires. Inspect connector and module pins for corrosion or damage.
2. 2

   Label and disconnect brake lines
   Using masking tape or a marker, label all four brake lines (LF, RF, LR, RR) before removal to ensure correct reinstallation. Using a 12mm flare nut wrench, carefully loosen each brake line fitting at the ABS module. Turn counterclockwise slowly to avoid rounding off the brass fittings. Once loose, unthread by hand and immediately plug lines with rubber caps or clean rags to prevent fluid loss and contamination.
   ⚠Use only a flare nut wrench on brake line fittings. Standard open-end wrenches will round off the soft brass fittings. If fittings are seized, apply penetrating oil and wait 15 minutes before attempting removal.
3. 3

   Remove ABS module mounting bolts
   Locate the two 10mm mounting bolts securing the ABS module to its bracket on the firewall. Using a 10mm socket, remove both bolts completely. Support the module with one hand as you remove the second bolt to prevent it from falling.
4. 4

   Remove ABS module assembly
   Carefully lift the ABS module assembly away from the firewall. Angle it to clear any surrounding components. Place the old module on a clean work surface. Brake fluid will continue to drip from the ports, so keep it over the drain pan. Note the orientation of the module for installation of the replacement.
5. 5

   Prepare new ABS module
   Remove the new ABS module from packaging. Verify part number matches the original. Remove protective caps from all four brake line ports. Install NEW sealing washers on each brake line (discard old washers). Do not reuse old washers as they will leak.
6. 6

   Install new ABS module
   Position the new ABS module onto the mounting bracket in the same orientation as the original. Hand-thread both mounting bolts to ensure proper alignment before tightening. Using a torque wrench and 10mm socket, torque both mounting bolts to specification in a cross pattern.
   Torque spec

   ABS Module Bolts10 Nm (7 lb-ft)
7. 7

   Reconnect brake lines
   Starting with the brake line positions you labeled earlier, thread each brake line fitting into the correct port on the ABS module by hand. Ensure at least 3-4 full turns by hand before using a wrench to confirm threads are not cross-threaded. Once all four lines are hand-tight, use the 12mm flare nut wrench and torque wrench to tighten each fitting to specification. Work in a star pattern (LF, RR, RF, LR) to ensure even seating.
   ⚠Cross-threading brake line fittings will cause catastrophic brake failure. If any resistance is felt while hand-threading, back out and restart. The fittings should thread smoothly by hand for several turns.
   Torque spec

   Brake Line Fittings15 Nm (11 lb-ft)
8. 8

   Reconnect electrical connector
   Align the ABS module electrical connector and push firmly until the locking tab clicks into place. Tug gently on the connector to verify it is fully seated and locked.
9. 9

   Refill brake fluid reservoir
   Fill the brake master cylinder reservoir to the MAX line with fresh DOT 3 brake fluid from a sealed container. Keep the reservoir at least half full throughout the bleeding process.
10. 10

    Perform manual brake bleeding
    Bleed brakes in this order: RR, LR, RF, LF. For each wheel: attach clear hose to bleeder screw, submerge other end in clean brake fluid in container. Have assistant pump brake pedal 3 times and hold. Open bleeder screw 3/4 turn, allow fluid to flow until pedal reaches floor, then close bleeder screw before releasing pedal. Repeat until no air bubbles appear (typically 5-10 repetitions per wheel). Torque each bleeder screw to specification after bleeding that wheel. Check and refill reservoir frequently.
    ⚠Never allow the master cylinder reservoir to run empty during bleeding or air will enter the system requiring the entire process to restart.
    Torque spec

    Bleeder Screw13 Nm (10 lb-ft)
11. 11

    Connect scan tool and verify communication
    Reconnect the negative battery terminal and tighten securely. Connect the Honda Diagnostic System (HDS) or equivalent professional scan tool to the OBD-II port under the driver side dashboard. Turn ignition to ON position (do not start engine). Verify the scan tool can communicate with the ABS module. Clear any diagnostic trouble codes that may have been set during the procedure.
12. 12

    Perform ABS automated bleeding procedure
    Using the scan tool, navigate to the ABS system menu and select the automated bleeding function. This will cycle the ABS pump and solenoids to purge air trapped in the modulator. Follow the on-screen instructions carefully. The scan tool will command the ABS pump to run for several cycles. Monitor brake fluid level closely and top off as needed. After the automated cycle completes, perform one additional manual bleeding sequence (RR, LR, RF, LF) to remove any remaining air displaced by the ABS cycling.
    ⚠️The automated ABS bleeding procedure is mandatory and cannot be skipped. Air trapped in the ABS modulator cannot be removed by manual bleeding alone and will cause brake failure during ABS activation.
13. 13

    Final fluid level check and inspection
    Fill the brake fluid reservoir to the MAX line with fresh DOT 3 fluid. Install the reservoir cap. With engine off, pump the brake pedal 20-30 times and verify firm pedal feel. The pedal should not sink slowly to the floor. Inspect all four brake line connections at the ABS module for any signs of fluid seepage. Wipe the area clean and observe for several minutes.

Reassembly

1. Reinstall engine cover by aligning clips and pressing down until they click into place
2. Remove all tools and drain pans from under vehicle
3. Clean any brake fluid spills from painted surfaces immediately with water

Verification

• Start engine and verify ABS warning light turns off after 2-3 seconds (normal bulb check). If ABS light remains on, retrieve codes with scan tool
• With engine running, apply firm brake pedal pressure and verify pedal is firm and does not slowly sink. There should be no sponginess
• Perform initial test drive in a safe, empty parking lot at low speed (10-15 mph). Make several moderate brake applications and verify normal pedal feel
• Perform controlled ABS activation test in safe area: on dry pavement at 20 mph, apply maximum braking force to activate ABS. Verify proper ABS pulsation through pedal and that vehicle stops straight without pulling
• After test drive, recheck brake fluid level and inspect all brake line connections at ABS module for leaks
• Final road test at normal speeds, verifying normal brake function and proper ABS operation
• Recheck brake fluid level after 24 hours and top off if necessary. Some fluid may be absorbed into the system

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