[35B] FOUR-WHEEL ANTI-SKID BRAKE SYSTEM (4ABS) - - CONSTRUCTION DESCRIPTION | PRINT PAGE / INDEX / PRIOR / NEXT

CONSTRUCTION DESCRIPTION The construction is basically the same as that of the LANCER, except the following:
G-SENSOR <4WD> The G-sensor detects fore-and-aft accelerations of a vehicle with semiconductors, and sends signals representing voltage values to ABS-ECU. The ABS-ECU estimates the vehicle speed required for control according to the signals from the G sensor and ABS sensor.
ACTUATORS
ABS WARNING LAMP The ABS warning lamp is controlled by the ABS-ECU. The warning lamp drive circuit in the combination meter contains an reversal circuit, which turns the ABS warning lamp off when the transistor in the ABS-ECU is ON and turns the lamp on when the transistor is OFF. When the system is normal, the ABS-ECU keeps the transistor ON. When it detects a system error, it turns the transistor OFF to turn the ABS warning lamp on. The ABS warning lamp also comes on when the ABS-ECU connector is disconnected.
ELECTRONIC CONTROL UNIT (ECU)
DIAGNOSTIC FUNCTIONS The ABS-ECU includes the following functions to make system inspection easier. All of the above operations can be carried out using the MUT-II/III. Diagnosis code output service data output Actuator testing
FAIL-SAFE FUNCTION
Diagnosis code No. | Item | Action during fail-safe operation
--- | --- | ---
ABS control | EBD control | ABS warning lamp
11 | Open circuit or short-circuit in ABS sensor (FR) | Control stopped if any faulty wheel detects | If faulty wheels include two rear wheels: Control stopped Other than the above: Control carried out | Illuminated
12 | Open circuit or short-circuit in ABS sensor (FL)
13 | Open circuit or short-circuit in ABS sensor (RR)
14 | Open circuit or short-circuit in ABS sensor (RL)
16 | Abnormal drop or rise in ABS-ECU power supply voltage | Control stopped | Control stopped (when high voltage) Control carried out (when low voltage) | Illuminated
21 | ABS sensor (FR) system | If any faulty wheel detects: Control stopped in all wheels | If faulty wheels include two rear wheels: Control stopped Other than the above: Control carried out | Illuminated
22 | ABS sensor (FL) system
23 | ABS sensor (RR) system
24 | ABS sensor (RL) system
32 | G sensor system <4WD> | Control stopped | Control carried out | Illuminated
41 | Solenoid valve (FR) system | System interrupted | System interrupted | Illuminated
42 | Solenoid valve (FL) system
43 | Solenoid valve (RR) system
44 | Solenoid valve (RL) system
51 | Valve relay ON problem | Control stopped | Control carried out | Illuminated
52 | Valve relay OFF problem | System interrupted | System interrupted | Illuminated
53 | Motor relay OFF problem | Control stopped | Control carried out | Illuminated
54 | Motor relay ON problem | System interrupted | Control carried out | Illuminated
55 | Motor system | Control stopped | Control carried out | Illuminated
63 | ABS-ECU abnormality | System interrupted | System interrupted | Illuminated
NOTE: Control stopped: Control is not carried out until the ignition switch is turned to the "LOCK" (OFF) position. However, if the problem returns to normal, control is carried out again. System interrupted: Control is not carried out until the ignition switch is turned to the "LOCK" (OFF) position.
DIAGNOSIS CODE INDICATION METHOD The diagnosis codes can be checked using the MUT-II/III, and also by the flashing of the ABS warning lamp. (Refer to Service Manual.)
DIAGNOSIS CODE CLEARING PROCEDURE The diagnosis codes can be cleared using the MUT-II/III or by special operation for the brake pedal. (Refer to Service Manual.)
SERVICE DATA OUTPUT The data input from all sensors and switches can be read using the MUT-II/III.
Item No. | Check item | Checking requirement | Normal value
--- | --- | --- | ---
11 | Front-right ABS sensor | Drive the vehicle | Vehicle speeds displayed on the speedometer and MUT-II/III are identical.
12 | Front-left ABS sensor
13 | Rear-right ABS sensor
14 | Rear-left ABS sensor
21 | ABS-ECU power supply voltage | Ignition switch power supply voltage and valve monitor voltage | 10 - 16 V
32 | G-sensor <4WD> | Ignition switch: ON When vehicle is parked on a level surface. | 2.4 - 2.6 V
When vehicle is being driven | 0.5 - 4.5 V
| ACTUATOR TEST
| The MUT-II/III can be used to force-drive all solenoid valves and the pump motor.
Item No. | Check item | Drive Contents
--- | --- | ---
01 | Solenoid valve for front-right wheel | Solenoid valves and pump motors in the hydraulic unit (simple inspection mode)
02 | Solenoid valve for front-left wheel
03 | Solenoid valve for rear-right wheel
04 | Solenoid valve for rear-left wheel

[35B] FOUR-WHEEL ANTI-SKID BRAKE SYSTEM (4ABS) - - CONSTRUCTION DESCRIPTION | PRINT PAGE / INDEX / PRIOR / NEXT

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