Electronic Brake Control Module: Service and Repair
ABS Control Module and Hydraulic Control Unit (ABSCM&H/U)REMOVAL
1) Disconnect the ground cable from battery.
2) Remove the air intake duct and air cleaner case from the engine compartment to facilitate removal of ABSCM&H/U.
3) Use compressed air to get rid of water around the ABSCM&H/U.
NOTE: Contact will be insufficient if the terminal gets wet.
4) Disconnect the ABSCM&H/U connector pulling up the lock lever.
CAUTION: Do not pull the harness when disconnecting connector.
5) Remove the harness clip.
6) Disconnect the brake pipes from ABSCM&H/U.
7) Wrap the brake pipe using a vinyl bag not to spill the brake fluid on the vehicle body.
CAUTION: When brake fluid is attached to the vehicle body, wash it off with water and wipe the water.
8) Remove the nuts and remove the ABSCM&H/U.
CAUTION:
^ Do not drop or bump the ABSCM&H/U.
^ Do not turn ABSCM&H/U upside down or place it sideways for storage.
^ Be careful that no foreign objects are mixed in ABSCM&H/U.
^ Be careful that no water enters inside the connectors.
9) Remove the ABSCM&H/U bracket.
INSTALLATION
1) Install the ABSCM&H/U bracket.
Tightening torque:33 Nm (3.3 kgf-m, 24 ft. lbs.)
2) Install the ABSCM&H/U aligning the groove of damper on ABSCM&H/U side with the pawl of bracket.
NOTE: Check the identification mark of ABSCM&H/U.
Tightening torque:7.5 Nm (0.76 kgf-m, 5.5 ft. lbs.)
3) Connect the brake pipes to their correct ABSCM&H/U connections.
Tightening torque:15 Nm (1.5 kgf-m, 10.8 ft. lbs.)
4) Using the cable clip, secure the ABSCM&H/U harness to bracket.
5) Connect the connector to ABSCM&H/U.
NOTE:
^ Be sure to remove all foreign matter from inside of the connector before connecting.
^ Ensure that the ABSCM&H/U connector is securely locked.
6) Connect the ground cable to ABSCM&H/U, and then apply anti-corrosive wax.
7) Install the air cleaner case and air intake duct.
8) Bleed air from the brake system.
REPLACEMENT
CAUTION:
^ Because the seal of ABSCM cannot be replaced, do not pull or peel it with lifting up.
^ Because the screw part of H/U deteriorates in every replacement procedure, do not perform the replacement more than five times on it. When the malfunction is found though the replacement that performed is less than five times, replace the H/U body.
^ Use new screws for installation of ABSCM.
^ When the sealing surface of ABSCM or H/U is dirty or damaged and it cannot be removed or repaired, replace it with new one.
1) Remove the ABSCM&H/U.
2) To prevent entering foreign matter and brake fluid leakage, plug the oil pressure port of ABSCM&H/U using screw plug and etc.
3) Set the pump motor part of removed ABSCM&H/U faces down in the vise.
NOTE: Before securing a part on a vice, place cushioning material such as wood blocks, aluminum plate or cloth between the part and vice.
4) Using TORT BIT E5, remove the four screws of ABSCM.
NOTE: Always use new screws.
5) Slowly remove the ABSCM upward from H/U.
NOTE: To prevent damaging of coil part, remove the ABSCM straightly from H/U.
6) Ensure there are no dirt or damage on sealing surface of H/U.
CAUTION:
^ Do not clean the ABSCM & H/U with applying compressed air.
^ Do not repair the damages of H/U sealing surface using file or metal scraper. To remove the sealing, use resin scraper. Do not use the chemical materials (thinner and etc.).
7) Position the coil of new ABSCM to align H/U valve.
8) To prevent deforming of ABSCM housing cover, hold the corner of ABSCM and install it to the H/U without tilting.
9) Using TORT BIT E5, tighten the screws stepwise in the order of (1) through (4).
CAUTION: Always use new screws.
Tightening torque:1.5 Nm (0.15 kgf-m, 1.1 ft. lbs.)
10) Check that there is no foreign matter in aligning part between ABSCM and H/U.
11) Using TORT BIT E5, tighten the screws stepwise in the order of (1) through (4) again.
Tightening torque: 3 Nm (0.3 kgf-m, 2.2 ft. lbs.)
12) Check that there is no clearance in aligning part between ABSCM and H/U.
13) Install the ABSCM&H/U to vehicle.
INSPECTION
1) Check the connected and fixed condition of connector.
2) Check specifications of the mark with ABSCM&H/U.
CHECKING THE HYDRAULIC UNIT ABS OPERATION BY PRESSURE GAUGE
1) Lift-up the vehicle and remove the wheels.
2) Disconnect the air bleeder screws from the FL and FR caliper bodies.
3) Connect two pressure gauges to the FL and FR caliper bodies.
CAUTION:
^ Pressure gauges used exclusively for brake fluid must be used.
^ Do not employ pressure gauge previously used for transmission oil pressure since the piston seal is expanded which may lead to malfunction of the brake.
NOTE: Wrap sealing tape around the pressure gauge.
4) Bleed air from the pressure gauges.
5) Perform the ABS sequence control.
6) When the hydraulic unit begins to work and first the FL side performs decompression, holding and compression, and then the FR side performs decompression, holding and compression.
7) Read values indicated on the pressure gauge and check if the fluctuation of the values between decompression and compression meets the standard values. Also check if any irregular brake pedal tightness is felt.
8) Remove the pressure gauges from FL and FR caliper bodies.
9) Remove the air bleeder screws from the RL and RR caliper bodies.
10) Connect the air bleeder screws to the FL and FR caliper bodies.
11) Connect two pressure gauges to the RL and RR caliper bodies.
12) Bleed air from the FL and FR caliper bodies.
13) Perform the ABS sequence control.
14) When the hydraulic unit begins to work, at first the RR side performs decompression, holding and compression, and then the RL side performs decompression, holding and compression.
15) Read values indicated on the pressure gauges and check if they meet the standard value.
16) After checking, remove the pressure gauges from caliper bodies.
17) Connect the air bleeder screws to RL and RR caliper bodies.
18) Bleed air from the brake system.
CHECKING THE HYDRAULIC UNIT ABS OPERATION WITH BRAKE TESTER
1) In the case of non-turbo AT model, install a spare fuse with the FWD connector in the main fuse box to simulate FWD model.
NOTE: The AWD circuit of MT and turbo AT model can not be disabled.
2) Prepare for operating the ABS sequence control.
3) Set the front wheels or rear wheels on the brake tester and set the select lever's position at "N" range.
4) Operate the brake tester.
5) Perform the ABS sequence control.
6) Hydraulic unit begins to work; and check the following working sequence.
(1) The FL side performs decompression, holding and compression in sequence, and subsequently the FR side repeats the cycle.
(2) The RR side performs decompression, holding and compression in sequence, and subsequently the AL side repeats the cycle.
7) Read values indicated on the brake tester and check if the fluctuation of values, while decompressed and compressed, meet the standard values.
8) After checking, also check if any irregular brake pedal tightness is felt.