Stabilizer Bar Disconnect (How it Works)

SteelBronco

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Information on the BWI stabilizer bar disconnect system which should be directly related to the Bronco Raptor.
BWI Bronco Front Stabilizer Bar Disconnect.jpg


Here is a picture of an actual unit.
Part Number: MB3Z-5482-C


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The front stabilizer bar disconnect feature consists of the following components;
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Bronco Stabilizer Bar Disconnect Operational Video


The stabilizer bar disconnect system is controlled by the CHCM. The CHCM is located behind the LH trim in the rear luggage compartment. The piston is connected to the inner ball screw, which is threaded to the outer ball screw. The outer ball screw is part of the stabilizer bar disconnect assembly housing.
When a disconnection is requested by the driver or by the CHCM, the solenoids open. The hydraulic fluid flushes in and out of the chambers on either side of the piston via the upper and lower return fluid pipes. This allows the hydraulic fluid to flow freely and the piston to move within the housing, rotating the inner ball screw. This action allows the LH stabilizer bar half shaft to operate independently of the RH stabilizer half shaft. Full suspension travel is available to each front wheel. When a re-connection is requested by the driver or the CHCM, the solenoid valves close, preventing fluid flow. The piston is now hydraulically locked, preventing the inner ball screw from rotating independently of the outer ball screw and the whole assembly rotates as one. Both ends of the stabilizer bar are re-connected, optimizing handling and reducing the amount body roll when cornering.

NOTE: The front stabilizer bar disconnect system is serviced as an assembly. Refer to the WSM for further information.

NOTE: In case of electrical failure, the system will default to the connected mode with the solenoids closed.

NOTE: In case of a loss of hydraulic pressure, the system will default to the disconnected mode, and a warning light will be displayed in the IPC. Vehicle handling characteristics will be degraded.

NOTICE: Do not get under a vehicle with engine ON as the stabilizer bar disconnect could activate and the vehicle could unexpectedly drop. Failure to follow this instruction could result in personal injury or death.

NOTICE: Fluid in the front stabilizer disconnect assembly is under very high pressure. The front stabilizer disconnect assembly is not serviceable. Failure to follow these instructions may result in serious personal injury.

The front stabilizer disconnect feature can be operated by pressing the switch in the SIMA which is located at the top center of the instrument panel. The system will only disconnect the stabilizer bar when the vehicle speed is below 32 km/h (20 mph) and it is in 4L or 4H. An amber indicator illuminates in the SIMA to show that the stabilizer bar is disconnected. Pressing the button again will reconnect the stabilizer bar.

The stabilizer bar will also be reconnected if:
  1. The engine is switched off.
  2. The driver switches from 4L or 4H to 2H or 4A.
  3. The driver selects a drive mode that does not allow for the stabilizer bar to be disconnected.
NOTE: The stabilizer bar disconnect button press information is transmitted on CAN from the SIMA to the ATCM to the CHCM, via the GWM.

NOTE: Any diagnosis of issues with the stabilizer bar disconnect button operation should include the SIMA, GWM and ATCM modules.

NOTE: The stabilizer bar system will also turn ON and disconnect the stabilizer bar when the Rock Crawl drive mode is selected.

NOTE: The stabilizer bar disconnect feature is not available in certain drive modes.
When the vehicle speed exceeds 32 km/h (20 mph), the stabilizer bar reconnects and a grey indicator illuminates, indicating the system is in standby mode. The stabilizer bar disconnects again once the vehicle speed is below 32 km/h (20 mph). If the vehicle speed is above 32 km/h (20 mph) and the system is on, the request is stored and a grey indicator illuminates to indicate that the system is in standby mode. When the vehicle speed falls below 32 km/h (20 mph), the stabilizer bar disconnects and the amber indicator illuminates, indicating that the stabilizer bar has disconnected.

NOTE: The grey indicator stays on until either the vehicle speed reduces and the stabilizer bar disconnects or, the system turns off.

NOTE: The stabilizer bar disconnect could be delayed during wheel slippage, dynamic maneuvers, dynamic cornering, or when there is an anti-lock brake system or electronic stability control event in progress.

NOTE: The stabilizer bar can be reconnected at any time, it is not necessary for the vehicle to be on a level surface as the stabilizer bar self-aligns.

Stabilizer bar disconnect - Drive mode availability options:
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STABILIZER BAR DISCONNECT INDICATORS

An indicator illuminates when you switch the stabilizer bar disconnect system on. The color of the indicator changes to indicate the system status.

Amber indicates that the stabilizer bar is disconnected.
Grey indicates that the stabilizer bar is connected and in standby.
Red indicates that there is a fault with the system, have the system checked as soon as possible.

NOTICE: If the stabilizer bar disconnect warning lamp illuminates red, a fault could be detected and the stabilizer bar could not be connected. Do not drive your vehicle above 32 km/h (20 mph) and have the system checked as soon as possible. Driving your vehicle above 32 km/h (20 mph) could reduce vehicle stability.

Component Description

CHCM

The CHCM is the logic module for the front stabilizer bar disconnect system. Multiple modules/system inputs are used for the front stabilizer bar disconnect system to enable the connection and disconnection of the stabilizer bar depending on the user request or the driving mode.

The CHCM require PMI when replaced.

Refer to: Module Configuration - System Operation and Component Description (418-01A Module Configuration, Description and Operation).
Refer to: Module Configuration - System Operation and Component Description (418-01B Module Configuration - Vehicles With: Over-the-Air (OTA) Programming, Description and Operation).

**Information and pictures taken from BWI and Bronco6G***
 

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