Mitsubishi Outlander: Anti-lock Braking System (ABS)

General Information

The 4ABS ensures directional skid and control during hard braking.

This ABS uses a 4-sensor system that controls all four wheels independently of each other.

• EBD *1control can obtain ideal rear wheel brake force.
• The magnetic encoder for wheel speed detection has been installed instead of the rotor as the wheel speed sensor.
• For wiring harness saving and secure data communication, CAN *2 bus has been adopted as a tool of communication with another ECU.
• Fail-safe function which ensures that safety is maintained.
• Diagnostic function which provides improved serviceability.

NOTE:

• *1: EBD (Electronic Brake-force Distribution)
• *2: For more details about CAN (Controller Area Network)

Specifications

CONSTRUCTION DIAGRAM

MAIN COMPONENTS AND FUNCTIONS

Service Specifications

ABS Diagnosis

INTRODUCTION

The anti-lock brake system (ABS) operates differently from conventional brake systems. These differences include sounds, sensations, and vehicle performance that owners and service technicians who are not familiar with ABS may not be used to.

Some operational characteristics may seem to be malfunctions, but they are simply signs of normal ABS operation. When diagnosing the ABS system, keep these operational characteristics in mind.

Inform the owner of the kind of performance characteristics to expect from an ABS-equipped vehicle.

ABS DIAGNOSTIC TROUBLE CODE DETECTION CONDITIONS

ABS diagnostic trouble codes (ABS DTCs) are set under different conditions, depending on the malfunction detected. Most ABS DTCs will only be set during vehicle operation. Some ABS DTCs will also be set during the ABS self-check immediately after the engine is started.

When you check if an ABS DTC will be displayed again after the DTC has been erased, you should duplicate the ABS DTC set conditions. Depending on the detection timing and set conditions for the specific ABS DTC, you must either drive the vehicle or turn the engine off and restart it. To set the proper conditions for that DTC again, refer to "ABS DTC SET CONDITIONS" for each ABS DTC that you are trying to reset.

ABS DIAGNOSTIC TROUBLESHOOTING STRATEGY

Use these steps to plan your diagnostic strategy. If you follow them carefully, you will be sure that you have exhausted most of the possible ways to find an ABS fault.

1. Gather information about the problem from the customer.

2. Verify that the condition described by the customer exists.

3. Check the vehicle for any ABS DTC.

4. If you cannot verify the condition and there are no ABS DTCs, the malfunction is intermittent. Refer to GROUP 00, How to use Troubleshooting/Inspection Service Points − How to Cope with Intermittent Malfunctions.

5. If you can verify the condition but there are no ABS DTCs, or the system cannot communicate with the scan tool, check that the basic brake system is operating properly.

• If the basic brake system is not operating properly, refer to the GROUP 35A, Basic Brake System Diagnosis.
• If the basic brake system is operating properly, refer to GROUP 35A, Brake Booster Operating Check.

6. If there is an ABS DTC, record the number of the DTC, then erase the DTC from the memory using the scan tool.

7. Recreate the ABS DTC set conditions to see if the same ABS DTC will set again.

• If the same ABS DTC sets again, perform the diagnostic procedures for the DTC.
• If you cannot get the same ABS DTC to set again, the malfunction is intermittent. Refer to GROUP 00, How to use Troubleshooting/Inspection Service Points − How to Cope with Intermittent Malfunctions.

ABS WARNING LIGHT AND BRAKE WARNING LIGHT CHECK

Check that ABS and brake warning lights illuminate as follows.

NOTE: The EBD warning light is also used as the brake warning light.

1. When the ignition switch is turned to the ON position, ABS and brake warning lights illuminate.

2. The ABS and brake warning lights illuminate for three seconds*1 and then turn OFF*2.

3. Otherwise, check the diagnostic trouble code.

NOTE:

• *1: The ABS warning light may stay ON until the vehicle speed reaches 6 mph (10 km/h). As far as ABS-ECU stores any diagnostic trouble code related to the wheel speed sensor malfunction or the motor malfunction as past trouble, ABS-ECU continues illuminating the ABS warning light until it verifies that the malfunction for that code is resolved (start-up check).
• *2: The brake warning light does not turn OFF when the parking brake is applied or the brake fluid level is lowered.

• Diagnosis Function
• Diagnostic Trouble Code Procedures
• Symptom Chart, Symptom Procedures
• On-vehicle Service
• Wheel Speed Sensor

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