Electronic Stability Program: Other Suzuki SX4 I рестайлинг

Precautions in On-Vehicle Service

When connector is connected to ESP® hydraulic unit/control module assembly, do not disconnect connectors of sensors with ignition switch ON. Otherwise, DTC will be set in ESP® control module.

ABS (Anti-lock Brake System)

This function prevents tire locking which may occur when brake is applied suddenly or on slippery roads. With this function, as the vehicle is kept in the stable state and tires unlocked, the driver can avoid any obstacle by turning the steering wheel.

EBD (Electronic Brake force Distribution)

This function distributes braking force of front and rear wheels properly according to the vehicle load condition. With this function, the braking force of the front and rear wheels is controlled for the optimum effect to secure the maximum braking force regardless of the loadage.

Traction Control

This function controls the engine and brake to prevent the driving wheels from spinning at the time of starting and accelerating.

Particularly, this function is helpful for safe driving on muddy or icy roads. When ESP® control module detects wheel spinning using information from the yaw rate sensor and wheel speed sensor, it lower the engine torque by closing the electronic controlled throttle and controlling ignition. At the same time, brake is applied to the spinning tire.

Stability Control

This function controls the vehicle in the stable state by controlling the engine and braking so as to prevent the vehicle from over-steering or under-steering while turning.

When under-steering occurs, this function lowers the engine torque and applies brake to the inner rear wheel in the vehicle forward direction so as to prevent the vehicle from moving outward.

When over-steering occurs, this function applies brake to the outer front wheel in the vehicle forward direction so as to prevent the vehicle from moving inward.

ESP® control module/hydraulic unit

The control module receives signals from each wheel speed sensor, ESP® OFF switch, brake master cylinder pressure sensor (7), steering angle sensor and yaw rate/G sensor. Based on these signals as information, the control module judges the vehicle conditions and controls the brake hydraulic pressure by combining the ON/OFF operation of the solenoid in the hydraulic unit and the pump motor operation.

The hydraulic unit contains an inlet solenoid valve (8) and an outlet solenoid valve (9) for each wheel as well as a cut solenoid valve (10) and a suction solenoid valve (11) for each hydraulic unit system. Also, a master cylinder pressure sensor, pump motor (6), etc. are included. The hydraulic pressure control is done in 3 modes of pressure increase, pressure keeping and pressure reduction.

Scheme 41

1. Pump motor: The pump motor turns on and applies pressure to each brake when braking is activated in the traction control and stability control state. When in the pressure reduction mode, it causes the brake fluid in the reservoir to return to the master cylinder (1).
2. Brake master cylinder pressure sensor: This sensor detects the brake hydraulic pressure in the primary piping when brake is applied in the normal condition. Also, it detects the pump motor driving state when brake is applied in the traction control and stability control state.
3. Inlet solenoid valve: In the ABS, traction control and stability control state, this valve is activated in the pressure keeping and pressure reduction modes to open the fluid passage, thereby restricting increase of the hydraulic pressure applied to the brake caliper.
4. Outlet solenoid valve: In the ABS, traction control and stability control state, this valve is activated in the pressure reduction mode to open the fluid passage, thereby lowering the hydraulic pressure kept in the brake caliper.
5. Cut solenoid valve: When brake is applied in the traction control and stability control state, this valve is activated to close the fluid passage, thereby causing the hydraulic pressure generated by the pump motor to apply to the brake caliper.
6. Suction solenoid valve: When brake is applied in the traction control and stability control state, this valve is activated to open the fluid passage from the master cylinder to the pump motor.

Steering angle sensor

The steering angle sensor is assembled with the contact coil as a unit and mounted to the steering column. Detecting the angle as the steering wheel is turned, it sends that information to the ESP® control module.

Yaw rate/G sensor

The yaw rate/G sensor consists of the yaw rate (angular velocity in the vehicle turning direction) sensor and right-left G (acceleration in right-left direction) sensor and is mounted to the P/S controller bracket at the lower part of the center console. It detects the angular velocity in the vehicle turning direction and movement in the right-left direction, and then it sends that information to ESP® control module.

Wheel speed sensor

The vehicle speed is detected by the hall IC type wheel speed sensor (1) and encoder (4). The wheel speed sensor is fixed to the knuckle and includes a hall IC (3) having 2 hall elements (2).

The encoder consisting of a permanent magnet which has S/N electrodes turns inside of the wheel hub along with the wheel. The wheel speed sensor outputs alternate current.

As the cycle of the alternate current is in proportion to the revolution speed of the encoder, this AC signal (5) is converted into the voltage signal in the ESP® control module (6) for detection of the wheel speed.

Scheme 42

ESP® OFF switch

This switch is momentary type. And this is attached to console box.

ESP® OFF light in combination meter lights up by pushing the switch more than 5 seconds.

Then it informs that ESP® (except for ABS) is controlled not to work to driver.

The operation of ESP® OFF is canceled when ignition switch is turned ON after ignition switch is turned OFF with ESP® OFF is operated.

On-Board Diagnosis System Description

ESP® control module is a component of ESP® hydraulic unit/control module assembly and has the following functions.

Self-Diagnosis Function

ESP® control module monitors each input and output signals. When ESP® control module detects any malfunction, some of ABS warning light (1), EBD warning light (brake warning light) (2), ESP® warning light (3), SLIP indicator light (4), ESP® OFF light (5) are turned ON and indicate the abnormality to driver.

Scheme 43

1. When ignition switch is turned ON, ABS warning light, EBD warning light, ESP® warning light, SLIP indicator light and ESP® OFF light lights for 2 seconds to check its circuit.
2. When no abnormality is detected (the system is in good condition), ABS warning light, EBD warning light, ESP® warning light, SLIP indicator light and ESP® OFF light turn OFF after 2 seconds.
3. When an abnormality in the system is detected, some of ABS warning light, EBD warning light (brake warning light), ESP® warning light, SLIP indicator light and/or ESP® OFF light are turned ON and the area where that abnormality lies is stored in the memory in ESP® control module.

Fail-Safe Mode

When ESP® control module detects abnormality, the system goes into fail-safe mode. And some of functions of ABS, traction control system, stability control system are shut down. For details of fail safe mode, refer to FAIL-SAFE TABLE .

Customer complaint analysis

Record details of the problem (failure, complaint) and how it occurred as described by the customer. For this purpose, use of such a questionnaire form as shown in the following will facilitate collecting information to the point required for proper analysis and diagnosis.

Customer questionnaire (Example)

CUSTOMER QUESTIONNAIRE REFERENCE CHART

Scheme 44

Step 4: ESP® Check

According to ESP® Check for the DTC confirmation in STEP 3: DTC CHECK , locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator assembly or other part and repair or replace faulty parts.

Step 6: Intermittent Problem Check

Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to INTERMITTENT AND POOR CONNECTION INSPECTION and related circuit of trouble code recorded in STEPS 1: MALFUNCTION ANALYSIS to STEP 3: DTC CHECK.

ABS Warning Light Check

Refer to ABS WARNING LIGHT CHECK .

EBD Warning Light (Brake Warning Light) Check

Refer to EBD WARNING LIGHT (BRAKE WARNING LIGHT) CHECK .

Scheme 45

1. Turn ignition switch to OFF position.
2. Connect SUZUKI scan tool to DLC (1). Special Tool (A): SUZUKI scan tool (SUZUKI-SDT)
3. Turn ignition switch to ON position.
4. Read DTC according to instructions displayed on SUZUKI scan tool and print it or write it down. Refer to SUZUKI scan tool operators manual for further details. NOTE: If SUZUKI scan tool can not communicate ESP® control module, perform «SERIAL DATA LINK CIRCUIT CHECK»(ref-514554-S15020463562012112100000) .
5. After completing the check, turn ignition switch off and disconnect SUZUKI scan tool from DLC.

ESP® Control Module

The parameter data below are values measured with the SUZUKI scan tool when the normally operating vehicle is under the following conditions. When taking measurements for comparison by using the SUZUKI scan tool, be sure to check that the vehicle is under the following conditions.

1. Parking brake is applied and wheels are blocked.
2. Ignition switch is at ON position.
3. Air conditioner is turned OFF (if equipped).
4. No load is applied to power steering (if equipped). (Do not turn it)
5. Set the wheel in straight-ahead position and hands off steering wheel.
6. All electric loads are turned OFF (except ignition).
7. No DTC is detected.

SCAN TOOL DATA

RF Wheel Speed Sensor, LF Wheel Speed Sensor, RR Wheel Speed Sensor, LR Wheel Speed Sensor (km/h)

Wheel speed is ESP® control module internal parameter. It is computed by reference pulses from the wheel speed sensor.

Battery Voltage (V)

Battery Voltage is an analog input signal read by the ESP® control module. Certain ESP® control module functions will be modified if the battery voltage falls below or rises above programmed thresholds.

Brake Switch (ON, OFF)

This switch signal informs the ESP® control module whether the brake is active or not.

Master Cyl Press (MPa)

Brake fluid pressure from brake master cylinder.

G Sensor (Lateral) (G)

Lateral acceleration is measured by yaw rate/G sensor and output to ESP® control module.

Right acceleration is displayed by "-", Left acceleration is displayed by "+".

Yaw Rate Sensor (deg/s)

Yaw rate sensor is measured by yaw rate/G sensor and output to ESP® control module.

Right turn is displayed by "-", Left turn is displayed by "+".

Steering Angle Sen (deg)

Steering wheel rotation angle is measured by steering angle sensor and output to ESP® control module.

Right turn is displayed by "-", Left turn is displayed by "+".

Engine Speed (RPM)

Engine speed computed by reference pulses from ECM.

Steering Angle Sig (Non N, neutral)

This indicates steering wheel angle measured by steering angle sensor is in straight-ahead or not.

ESP® Off State (Cont) (ON, OFF)

State of ESP®.

Inlet Solenoid RF, Inlet Solenoid LF, Inlet Solenoid RR, Inlet Solenoid LR (ON, OFF)

This parameter indicates the operational condition of the inlet solenoid valve.

Outlet Solenoid RF, Outlet Solenoid LF, Outlet Solenoid RR, Outlet Solenoid LR (ON, OFF)

This parameter indicates the operational condition of the outlet solenoid valve.

Cut Solenoid No. 1, Cut Solenoid No. 2 (ON, OFF)

This parameter indicates the operational condition of left-front or right-rear commutation solenoid valve (No. 1), or right-front or left-rear commutation solenoid valve (No. 2).

Suction Solenoid No. 1, Suction Solenoid No. 2 (ON, OFF)

This parameter indicates the operational condition of left-front or right-rear high pressure switching solenoid valve (No. 1), or right-front or left-rear high pressure switching solenoid valve (No. 2).

Pump Motor Driver (ON, OFF)

This parameter indicates the operational condition of the pump motor driver (transistor).

Valve Power Driver, (ON, OFF)

ESP® control module monitors the supply voltage to solenoid valve power supply driver. If the voltage is supplied, ON is displayed.

Scheme 46

ABS Warning Light Does Not Come ON at Ignition Switch ON

Refer to ABS WARNING LIGHT DOES NOT COME ON AT IGNITION SWITCH ON .

ABS Warning Light Comes ON Steady

Refer to ABS WARNING LIGHT COMES ON STEADY .

EBD Warning Light (Brake Warning Light) Comes ON Steady

Refer to EBD WARNING LIGHT (BRAKE WARNING LIGHT) COMES ON STEADY .

Serial Data Link Circuit Check

Refer to SERIAL DATA LINK CIRCUIT CHECK .

Scheme 47

For 4WD model

For Removal and Installation of rear wheel speed sensor (included in rear wheel hub), refer to REAR WHEEL HUB ASSEMBLY REMOVAL AND INSTALLATION (REAR DISC BRAKE MODEL) .

For 2WD model

Refer to REAR WHEEL SPEED SENSOR REMOVAL AND INSTALLATION .