Ford Explorer: Power Brake Actuation / Description and Operation - Power Brake System - System Operation and Component Description

Ford Explorer 2020-2024 Service Manual / Chassis / Brake System / Power Brake Actuation / Description and Operation - Power Brake System - System Operation and Component Description

System Operation

System Diagram - Electric Brake Boost

E347819 *.sttxt { visibility: hidden; } *.stcallout { visibility: visible; } HS-CAN3 HS-CAN1 HS-CAN2 1 IPC 2 RCM 3 BCM 4 PCM 5 GWM 6 ABS/EBB 7 Wheel speed sensors 8 Brake pedal

Item	Description
1	IPC
2	RCM
3	BCM
4	PCM
5	GWM
6	ABS/ EBB
7	Wheel speed sensors
8	Brake pedal

Network Message Chart

Module Network Input Messages - ABS Module

Broadcast Message	Originating Module	Message Purpose
Accelerator pedal position	PCM	This message is first sent to the GWM and then to the ABS module. The ABS module uses accelerator pedal position information for correct operation of the traction control, hill start assist and EPB drive away release features.
Battery low state of charge	BCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of a low battery voltage event as measured by the BCM.
Battery voltage	BCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current battery and charging system voltage.
Brake pedal applied	PCM	This message is sent to the GWM and then to the ABS module. Used to inform the ABS module the driver has pressed the brake pedal and notifies the ABS module if the data is valid or invalid. This message is used by the ABS module to monitor and control anti-lock brake operations, traction control, ESC, RSC and hill start assist operations.
Clutch pedal data	PCM	This message is sent to the GWM and then to the ABS module. This message informs the ABS module of the current clutch pedal position as a percentage of total travel and if the information is within specifications, faulty or does not exist.
Driven wheel torque output	PCM	This message is sent to the GWM and then to the ABS module. This message informs the ABS module of the current torque output available at the driven wheels. This information is used for the traction control, hill start assist, ESC and RSC feature operation.
EPAS external angle request	PAM	This message is sent to the GWM and then to the ABS module. This message informs the ABS module the EPAS gear is in the process of completing a park aid steering request
Engine RPM data	PCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current engine speed in RPM.
Engine status	PCM	This message is sent to the GWM and then to the ABS module. This message informs the ABS module of the current engine status; engine off, engine on, engine auto stopped, not used.
Gear lever position	PCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current driver selected gear. The hill start assist feature works in forward and reverse gears. The ESC does not operate when the transmission is in REVERSE.
Ignition status	BCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current ignition status; off, accessory, run, start, unknown or invalid.
Parking brake status	BCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current parking brake status of the mechanical parking brake system; active or inactive.
Reverse gear status	PCM	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current reverse gear status: inactive not confirmed, inactive confirmed, active not confirmed, active confirmed or fault. The hill start assist feature works in forward and reverse gears. The ESC does not operate when the transmission is in REVERSE.
Traction control switch status	IPC	This message is first sent to the GWM and then to the ABS module. This message informs the ABS module of the current traction control switch status; pressed or not pressed.
Vehicle configuration data	BCM	This message is first sent to the GWM and then to the ABS module. This message provides the ABS module with the current optional and configured items such as, tire size, axle ratio, manual or automatic transaxle, keyless entry, and VIN.
Vehicle stability control data	RCM	This message provides the ABS module with the following stability control information; longitudinal acceleration, lateral acceleration, yaw rate and roll rate. The ABS module uses this information to help maintain vehicle stability during maneuvers.

Electric Brake Boost

The Electric Brake Boost EBB is an integral function of the ABS HCU. The ABS monitors brake pedal input, brake fluid pressure, vehicle speed and determines the amount of pedal assist needed. The brake pedal is only an input to the ABS module / HCU assy and doesn't normally create the hydraulic pressure to apply the brakes. This is accomplished inside the HCU unit by the internal pump motor which applies force to the Linear Actuator.

Component Description

ABS Module

The ABS module is attached directly to the HCU and is not available separately for service. The ABS module is the ECU for all of the ABS and stability control systems, parking brake and electric brake boost. The ABS module monitors all sensor inputs and all CAN messages relating to ABS , stability control and driver input, then directly controls the solenoid valves and the hydraulic pump motor in the HCU. When an ABS, EBB or stability control system fault has been corrected or a new component has been installed, the ABS module must be programmed or calibrated using a diagnostic scan tool. The calibration procedure is required for the stability control sensors to learn the zero-position of the vehicle. The calibration procedure requires the vehicle to be on a level surface and not moving. The calibration procedure (IVD Initialization) is carried out using a diagnostic scan tool. The vehicle must also be driven over 20 km/h (12 mph) for at least 1 minute on a fairly straight road which allows the ABS module to find the steering angle center.

Hydraulic Control Unit

The HCU contains the Linear actuator, solenoid valves, the hydraulic pump motor and the pressure sensors used by the ABS for EBB, ABS and the various stability control systems. The ABS module and the HCU are attached directly together and not serviced seperately. The brake fluid reservior is the only servicable component on the HCU assy. A new HCU comes with a new ABS module. When a new HCU assembly is installed, it must be programmed with the vehicle configuration information and programmed with the latest level of module software. These procedures are carried out using a diagnostic scan tool. Follow all scan tool instructions. For additional information,
Refer to: Module Programming (418-01) .

When an ABS, stability control system or EBB fault has been corrected or a new component has been installed, the ABS module must be calibrated. The calibration procedure is required for the stability control sensors to learn the zero-position of the vehicle. The calibration procedure requires the vehicle to be on a level surface and not moving. The calibration procedure (IVD Initialization) is carried out using a diagnostic scan tool. The vehicle must also be driven over 20 km/h (12 mph) for at least 1 minute on a fairly straight road which allows the ABS module to find the steering angle center.

This system does not incorporate a traditional master cylinder as a separate component. The master cylinder is now part of the HCU. All brake system function is controlled by the ABS module / HCU assy. The brake fluid reservior is the only servicable component on the HCU assy.

Linear Actuator

The Linear Actuator controls all pressure within the brake system. It is an integral component to the HCU and cannot be serviced seperately.

Description and Operation - Power Brake System - Overview

Electric Brake Boost Overview The power assisted brake system utilizes an EBB. The EBB is an integrated function of the ABS / HCU assembly and is controlled by the ABS module...

Diagnosis and Testing - Power Brake System

Other information:

Ford Explorer 2020-2024 Service Manual: Removal and Installation - High-Pressure Fuel Pump

Removal NOTICE: Fuel injection equipment is manufactured to very precise tolerances and fine clearances. To prevent fuel system damage, it is essential that absolute cleanliness is observed when working with these components. NOTICE: Do not loosen any fittings or plugs on the high-pressure fuel pump...

Ford Explorer 2020-2024 Owners Manual: Instrument Panel

A - Air vents. B - Direction indicator. See Direction Indicators. C - Cruise control. See Cruise Control. Audio control. See Audio Control. D - Information display. See General Information. E - Information display control. See Information Display Control...