The ABS power unit is located in the driver-side of the engine compartment. See Fig 1 . The ABS power unit consists of an electrically driven hydraulic pump, an ABS pressure switch unit and an accumulator. The pump includes a non-return valve and a pressure relief valve to protect hydraulic system from over pressurization. The pump is powered through the ABS pump relay and the ABS pressure switch unit.

The ABS pressure switch unit incorporates 3 pressure switches. One switch turns hydraulic pump on and off. A second switch, set at a lower pressure setting, sends a signal to ABS ECU which sends a signal to Body Electronic Control Module (BECM) to operate BRAKE warning light. When pressure drops too low, the second and third switches send signals to ABS ECU which deactivates pump. If there is a hydraulic pump or pressure switch unit failure, ABS power unit must be replaced.

The accumulator is a diaphragm type used to store hydraulic energy. The accumulator is precharged with approximately 1160 psi (82 kg/cm² ) of nitrogen and is serviced separately.

Fig 1: Identifying ABS Hydraulic Brake Circuits & Components

Courtesy of LAND ROVER NORTH AMERICA, INC.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Abs Power Unit

Use the Manual With the Right Hardware

When to See a Mechanic

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