Traction Control: Overview Mitsubishi Eclipse III

GENERAL DESCRIPTION

If the throttle is opened excessively when a vehicle is started or accelerated, the driving wheels may slip due to excessive drive torque. This adversely affects startability, accelerating ability or controllability. To ensure startability, accelerating ability and controllability, this TCL system will prevent wheel slip by controlling (applying) brake fluid pressure to the drive wheels to adjust the driving torque according to road conditions. Each wheel-speed sensor detects wheel speed and converts it to an electric signal. The ABS-ECU determines which wheel begins to slip according to that signal. If the ABS-ECU determines wheel slip, it activates the solenoid valves and the pump inside the hydraulic unit to prevent the wheel slip by applying brake ensuring controllability. This TCL system is controlled by the ABS-ECU, and the TCL components are shared by the ABS system. If the ABS hydraulic unit is faulty, the ABS-ECU must be replaced.

Scheme 104

Scheme 105

ABS Operation Sounds and Sensations

During normal operation, the ABS makes several sounds that may seem unusual at first

A whining sound is caused by the ABS hydraulic unit motor.

BY SPECIAL OPERATION FOR BRAKE PEDAL

Required Special Tool

1. MB991529: Diagnostic Trouble Code Check Harness

Scheme 106

1. Use special tool MB991529 to ground number 1 terminal of the data link connector. NOTE: If the ABS-ECU functions have stopped due to the fail-safe function, the diagnostic code cannot be erased.
2. Depress the brake pedal and hold it.
3. Turn the ignition switch to the "ON" position.
4. After turning the ignition switch to the "ON," release the pedal within three seconds. Repeat this process of pressing and releasing the brake pedal 10 continuous times.
5. Turn the ignition switch to the "LOCK" (OFF) position.
6. Disconnect special tool MB991529.

CIRCUIT OPERATION

Power is continuously supplied to the ABS-ECU through fusible link number 3 to operate the solenoid valves and motor. The ABS-ECU supplies power to the solenoids. If controls each solenoid by switching the ground circuit ON or OFF, depending on driving conditions.

1. The diagnostic output is made from the ABS-ECU (terminal 11) to the diagnostic output terminal (terminal 7) of the data link connector.
2. When the data link connector's diagnostic test mode control terminal (terminal 1) is grounded, the ABS-ECU (terminal 12) will switch to the diagnostic mode.

TECHNICAL DESCRIPTION (COMMENT)

When communication with the scan tool is not possible, the cause is probably an open circuit in the ABS-ECU power circuit or an open circuit in the diagnostic output circuit.

1. Power to the TCL indicator light is supplied from the ignition switch. The ABS-ECU grounds the circuit to turn the light ON.
2. The ABS-ECU illuminates the TCL indicator light for three seconds on start-up < ignition key: "ON" (with engine stopped) >. When the ABS-ECU completes the self-check, it turns off the light.

The cause may be: an open circuit in the TCL indicator light power supply circuit, a blown TCL indicator light bulb or ABS-ECU malfunction.

1. Power to the TCL warning light is supplied from the ignition switch. The ABS-ECU grounds the circuit to illuminate the light.
2. The ABS-ECU illuminates the TCL warning light for three seconds on start-up < ignition key: "ON" (with engine stopped) >. When the ABS-ECU completes the self-check, it turns off the light.

The cause may be: an open circuit in the TCL warning light power supply circuit, a blown TCL warning light bulb or ABS-ECU malfunction.

1. The ABS-ECU controls the illumination of the TCL indicator light by turning the transistor in the ECU "ON and "OFF."
2. The ABS-ECU illuminates the TCL indicator light for three seconds on start-up < ignition key: "ON" (with engine stopped) >. When the ABS-ECU completes the self-check, it turns off the light.

The cause is probably the hydraulic unit (integrated with ABS-ECU) malfunction.

1. The ABS-ECU controls the illumination of the TCL warning light by turning the transistor in the ECU "ON" and "OFF."
2. The ABS-ECU illuminates the TCL warning light for three seconds on start-up < ignition key: "ON" (with engine stopped) >. When the ABS-ECU completes the self-check, it turns off the light.

The cause is probably hydraulic unit (integrated with ABS-ECU) malfunction.

The cause depends on driving and road surface conditions, so diagnosis may be difficult. However, if no diagnostic trouble code is displayed, carry out the following inspection.