Vehicle Stability Control System (Diagnostic Codes & Symptom Tests): Overview Lexus LX J200 рестайлинг

DESCRIPTION

The circuit is used to send control information from the skid control ECU (master cylinder solenoid) to the ECM, and engine control information from the ECM to the skid control ECU (master cylinder solenoid) via the CAN communication system.

After replacing the skid control ECU (master cylinder solenoid) or clearing the system information stored in the skid control ECU (master cylinder solenoid), the system information must be stored in the skid control ECU (master cylinder solenoid) again. The system information is automatically stored in the skid control ECU (master cylinder solenoid) when the system enters test mode. If the system information is not stored in the skid control ECU (master cylinder solenoid), DTC C120A is stored.

The skid control ECU (master cylinder solenoid) receives signals from the yaw rate sensor assembly via the CAN communication system.

The yaw rate sensor assembly has a built-in acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2). If there is trouble in the bus lines between the yaw rate sensor assembly and the CAN communication system, DTCs U0123 (yaw rate sensor communication trouble) and U0124 (acceleration sensor communication trouble) are stored.

The DTCs are also stored when the calibration has not been completed.

The solenoid turns on when signals are received from the skid control ECU (master cylinder solenoid) and controls the pressure acting on the wheel cylinders, thus controlling braking force.

Scheme 18

The skid control ECU (master cylinder solenoid) receives signals from the yaw rate sensor assembly via the CAN communication system.

The yaw rate sensor assembly has a built-in acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2). If there is trouble in the bus lines between the yaw rate sensor assembly and the CAN communication system, DTCs U0123 (yaw rate sensor communication trouble) and U0124 (acceleration sensor communication trouble) are stored.

Scheme 19

If the voltage supplied to the IG1 terminal is within the DTC detection range due to malfunctions in components such as the battery and generator circuit, this DTC is stored.

Scheme 20

If there is a problem with the skid control ECU (master cylinder solenoid) power supply circuit, the skid control ECU (master cylinder solenoid) stores DTCs and prohibits operation under the fail-safe function.

If the voltage supplied to the IG2 terminal is within the DTC detection range due to malfunctions in components such as the battery and generator circuit, this DTC is stored.

Scheme 21

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

HINT

The pump motor continues operation for the first 3 minutes, and then starts and stops repeatedly.

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

Scheme 22

The accumulator pressure sensor is connected to the skid control ECU in the master cylinder solenoid.

Scheme 23

Refer to DTC C1254. Refer to «DESCRIPTION».

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

DTC C1282 is stored only in test mode.

Scheme 24

The skid control ECU (master cylinder solenoid) communicates with the steering control ECU via CAN communication.

If a malfunction in the VGRS system is detected, cooperative control of the steering is prohibited by the fail-safe function.

The skid control ECU (master cylinder solenoid) acquires steering angle sensor zero point every time the engine switch is turned on (IG) and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The skid control ECU (master cylinder solenoid) also stores the previous zero point.

If the front wheel alignment or steering wheel position is adjusted without disconnecting the cable from the negative (-) battery terminal, or if the yaw rate and acceleration sensor zero point is not acquired after the adjustments have been completed, the skid control ECU (master cylinder solenoid) detects the difference between the previous zero point and newly acquired zero point and stores this DTC to indicate poor adjustment.

The steering angle sensor zero point malfunction warning is canceled by turning the engine switch off.

The skid control ECU (master cylinder solenoid) measures the speed of each wheel by receiving signals from the speed sensor. These signals are used for recognizing that all 4 wheels are operating properly. Therefore, all wheel signals must be equal.

Scheme 25

DTC C1379 is cleared when the CRAWL switch (integration control and panel assembly) sends a CRAWL switch (integration control and panel assembly) operation signal or when test mode ends.

Scheme 26

Upon receiving the hill-start assist control operating signal from the skid control ECU (master cylinder solenoid), the relay contact turns on and the stop light comes on.

Scheme 27

The skid control ECU (master cylinder solenoid) receives signals from the yaw rate sensor assembly via the CAN communication system.

The yaw rate sensor assembly has a built-in acceleration sensor and detects the vehicle's condition using 2 circuits (GL1, GL2).

If there is trouble in the bus lines between the yaw rate sensor assembly and the CAN communication system, DTCs U0123 (malfunction in CAN communication with the yaw rate sensor) and U0124 (malfunction in CAN communication with the acceleration sensor) are stored.

These DTCs are also stored when calibration has not been completed.

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU (master cylinder solenoid). These signals are used for brake control.

HINT

When the connectors between the speed sensor and skid control ECU (master cylinder solenoid) are connected, the following waveform is output.

Scheme 28

HINT

1. DTCs C1401 and C1271 are for the front speed sensor RH.
2. DTCs C1402 and C1272 are for the front speed sensor LH.

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTCs C1403 and C1273 are for the rear speed sensor RH.
2. DTCs C1404 and C1274 are for the rear speed sensor LH.

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTC C1405 is for the front speed sensor RH.
2. DTC C1406 is for the front speed sensor LH.

Scheme 29

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTC C1407 is for the rear speed sensor RH.
2. DTC C1408 is for the rear speed sensor LH.

Scheme 30

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTC C1409 is for the front speed sensor RH.
2. DTC C1410 is for the front speed sensor LH.

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTC C1411 is for the rear speed sensor RH.
2. DTC C1412 is for the rear speed sensor LH.

Refer to DTCs C1401 and C1402. Refer to «DTC C1401: Front Speed Sensor RH Malfunction; DTC C1271: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272: Low Output Signal of Front Speed Sensor LH (Test Mode DTC); DTC C1402: Front Speed Sensor LH Malfunction».

HINT

1. DTCs C1413 and C1275 are for the front speed sensor RH.
2. DTCs C1414 and C1276 are for the front speed sensor LH.

Refer to DTCs C1401 and C1402. Refer to «DESCRIPTION».

HINT

1. DTCs C1415 and C1277 are for the rear speed sensor RH.
2. DTCs C1416 and C1278 are for the rear speed sensor LH.

If a malfunction is detected in the power supply circuit, the skid control ECU (master cylinder solenoid) stores this DTC and the fail-safe function prohibits ABS/VSC/TRAC operation.

This DTC is stored when the IG1 terminal voltage deviates from the DTC detection condition due to a malfunction in the power supply or charging circuit such as the battery or generator circuit, etc.

This DTC is cleared when the IG1 terminal voltage returns to normal.

The skid control ECU (master cylinder solenoid) receives signals from the yaw rate sensor assembly via the CAN communication system.

The yaw rate sensor assembly has a built-in acceleration sensor and detects the vehicle condition using 2 circuits (GL1, GL2).

If there is trouble in the bus lines between the yaw rate sensor assembly and the CAN communication system, DTCs U0123 (malfunction in CAN communication with the yaw rate and acceleration sensor) and U0124 (malfunction in CAN communication with the acceleration sensor) are stored.

These DTCs are also stored when calibration has not been completed.

Refer to DTCs C1419 and C1435. Refer to «DESCRIPTION».

The pressure control sensor and master cylinder pressure sensor are connected to the skid control ECU in the master cylinder solenoid.

Scheme 31

Refer to DTCs C1421, C1423, C1424, C1455, C1457 and C1458. Refer to «DESCRIPTION».

The skid control ECU (master cylinder solenoid) has an open detection circuit, which stores this DTC when detecting an open in the stop light switch input line or the ground line of the stop light switch circuit with the stop light switch off (brake pedal not depressed).

Scheme 32

Steering sensor signals are sent to the skid control ECU (master cylinder solenoid) via the CAN communication system. When there is a malfunction in the CAN communication system, it is detected by the steering angle sensor zero point malfunction diagnostic function.

Scheme 33

Steering angle sensor signals are sent to the skid control ECU (master cylinder solenoid) via the CAN communication system. When there is a malfunction in the CAN communication system, it is detected by the steering angle sensor zero point malfunction diagnostic function.

Steering sensor signals are sent to the skid control ECU (master cylinder solenoid) via the CAN communication system. When there is a malfunction in the CAN communication system, it is detected by the steering sensor zero point malfunction diagnostic function.

Refer to DTC C1419 and C1435. Refer to «DESCRIPTION».

The skid control ECU (master cylinder solenoid) receives signals from the ECM via the CAN communication system.

The skid control ECU (master cylinder solenoid) acquires steering sensor zero point every time the engine switch is turned on (IG) and the vehicle is driven at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores the previous zero point.

The steering sensor zero point malfunction warning is canceled by turning the engine switch off.

If the skid control ECU (master cylinder solenoid) determines that the vehicle is being driven at a steep bank angle, the skid control ECU (master cylinder solenoid) stores DTC C1440 while VSC operation is temporarily disabled.

It is not a malfunction if the system and sensor circuits are normal and if the normal VSC operation resumes, which automatically clears DTC C1440, after the vehicle is returned to a normal position.

HINT

DTC C1440 and the yaw rate sensor assembly DTC are stored when the skid control ECU (master cylinder solenoid) determines that the vehicle is being driven at a steep bank angle and either of the following conditions is met

1. The yaw rate sensor assembly is installed at an angle.
2. The yaw rate sensor assembly signal output is stuck.

The skid control ECU (master cylinder solenoid) receives signals from the yaw rate sensor assembly via the CAN communication system.

The yaw rate sensor assembly has a built-in acceleration sensor.

The brake fluid level warning switch (brake master cylinder reservoir sub-assembly) sends the appropriate signal to the skid control ECU (master cylinder solenoid) when the brake fluid level drops.

Scheme 34

The solenoid relay is built into the master cylinder solenoid.

This relay supplies power to each solenoid. If the initial check is OK, after the engine switch is turned on (IG), the relay turns on.

If any of the following is detected, the ABS warning light remains on.

1. The skid control ECU (master cylinder solenoid) connectors are disconnected from the skid control ECU (master cylinder solenoid).
2. There is a malfunction in the skid control ECU (master cylinder solenoid) internal circuit.
3. There is an open in the harness between the combination meter and skid control ECU (master cylinder solenoid).

HINT

There is a case that the Techstream cannot be used when the skid control ECU (master cylinder solenoid) is abnormal.

Scheme 35

Refer to ABS Warning Light Remains ON. Refer to «DESCRIPTION».

When CRAWL starts after operating the CRAWL switch (integration control and panel assembly), the CRAWL indicator light turns on. While CRAWL is in the process of stopping, the CRAWL indicator light begins blinking. When CRAWL totally stops, the CRAWL indicator light turns off.

Scheme 36

Refer to Crawl Indicator Light Remains ON. Refer to «DESCRIPTION».

Refer to Multi-terrain Select Indicator Light does not Come ON. Refer to «DESCRIPTION».

When the transfer gear position is L4, the multi-terrain select indicator light illuminates and control begins.

Under any of the following conditions, the multi-terrain select system does not begin control and the multi-terrain select indicator light does not illuminate.

1. The vehicle is in the VSC/TRAC OFF state.
2. Crawl Control is operating.
3. There is a malfunction in the VSC system.

The brake warning light comes on when brake fluid is insufficient, the parking brake is applied or the EBD is defective.

Scheme 37

Refer to Brake Warning Light Remains ON. Refer to «DESCRIPTION».

The TRAC OFF indicator light comes on when the VSC OFF switch (combination switch assembly) is operated.

When there is a malfunction in the engine control system, TRAC OFF indicator light comes on and TRAC operation stops.

Scheme 38

Refer to TRAC OFF Indicator Light Remains ON. Refer to «DESCRIPTION».

Operation of the VSC OFF switch (combination switch assembly) changes the vehicle between normal mode, TRAC OFF mode and VSC OFF mode. During normal mode, pressing the VSC OFF switch (combination switch assembly) for a short amount of time changes vehicle to TRAC OFF mode. When the vehicle is stopped, pressing the VSC OFF switch (combination switch assembly) for 3 seconds or more changes the vehicle to VSC OFF mode.

When the transfer is in L4, the VSC OFF indicator light turns on.

Refer to VSC OFF Indicator Light Remains ON. Refer to «DESCRIPTION».

The slip indicator light blinks during VSC, A-TRAC, Crawl Control and hill-start assist control operation.

When the system fails, the slip indicator light comes on to warn the driver.

Scheme 39

Refer to Slip Indicator Light Remains ON. Refer to «DESCRIPTION».

When any of the following conditions are met, the turn assist system becomes operable and the turn assist indicator light illuminates.

1. Crawl Control is operating.
2. The turn assist function switch (integration control and panel assembly) is on.
3. The center differential is "free".
4. The vehicle is moving at a speed of 10 km/h (6 mph) or less.
5. The shift lever is not in P, R or N.

Scheme 40

The skid control buzzer sounds upon receiving a signal from the skid control ECU (master cylinder solenoid).

Scheme 41

The skid control ECU (master cylinder solenoid) is connected to the combination meter via CAN communication.

The combination meter has a built-in buzzer.

Scheme 42

DTC output mode is set by connecting terminals TC and CG of the DLC3.

The DTCs are output by the blinking of the ABS warning light and slip indicator light.

Scheme 43

HINT

When each warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.

The signal check circuit detects trouble in the sensor or switch signal which cannot be detected by the DTC check.

Connecting terminals TS and CG of the DLC3 starts the check.

Scheme 44

See also:
• ADJUSTMENT [01/2012 - ]
• ON-VEHICLE INSPECTION [01/2012 - ]
• REMOVAL [01/2012 - ]