The ABS relay and pump/motor relay are serviced together as an assembly with the relay box. The relay box mounts directly to the HCU. To remove the relay box from the HCU, you must remove the HCU from the vehicle. This must be done to allow visual access of the relay box-to-HCU electrical connection. Visual access to this connection is necessary to be sure the connection is properly made when installing the relay box on the HCU.
REMOVAL & INSTALLATION
See Figures 1, 2 and 3
- Disconnect the negative battery cable, then wrap it with insulated tape in order to isolate it.
- Remove the Hydraulic Control Unit (HCU) from the vehicle, as outlined in this section.
- Unclip the 6-way electrical connector from the relay box.
- Unfasten the 2 screws attaching the relay box to the HCU. Remove ONLY the 2 screws mounting the relay box to the HCU; do NOT remove the pump motor mounting screws.
- Grasp the relay box. Without rocking or twisting, pull the relay box away from the pump motor housing until the connector on the relay box unplugs from the pump motor terminal. This is a tight connection and will require some effort to separate from the pump motor.
- Remove the relay box from the HCU.
- Make sure the electrical connector seal in installed in the pump motor housing before installation of the relay body. If the seal is in any way damaged, it must be replaced before the relay box is installed.
- Position the relay box on the HCU, and carefully align the terminals on the relay box with the terminals on the pump motor.
- Hold the relay box with both hands. Then, without rocking or twisting, push the relay box onto the pump motor electrical connector as far as you can.
- Install and securely tighten the 2 screws attaching the relay box assembly to the HCU.
- Attach the 6-way connector to the onto the relay box.
- Install the HCU and master cylinder assemblies, as outlined earlier in this section.
- Connect the negative battery cable.
- Bleed the base brake system in the usual fashion, then bleed the ABS system following the correct sequences and procedure.
- Road test the vehicle to be sure the brake system is working properly.