Electronically Controlled Brake System (Diagnostics - Introduction): Other Lexus GS IV

PRECAUTION [03/2012 - ]

1. TROUBLESHOOTING PRECAUTIONS When there is a malfunction with terminal contact points or part installation problems, removal and installation of the suspected problem parts may return the system to the normal condition either completely or temporarily. In order to determine the malfunctioning area, be sure to check the conditions at the time the malfunction occurred, such as DTC output and the Freeze Frame Data, and record it before disconnecting each connector or removing and installing parts. Since the system may be influenced by malfunctions in systems other than the brake control system, be sure to check for DTCs in other systems.
2. HANDLING PRECAUTIONS Do not remove or install electronically controlled brake system parts such as the steering sensor, yaw rate sensor or brake pedal stroke sensor assembly except when required, as they cannot be adjusted correctly after removal or installation. When replacing the skid control ECU assembly, always install a new one. NOTE: Do not use the skid control ECU assembly from another vehicle (vehicle on display, etc.). Be sure to perform preparation before work and confirmation after work is completed by following the directions in the service information when working on the electronically controlled brake system. Be sure that the power switch is off when removing and installing the ECU, actuator, each sensor, etc. unless it is specified otherwise in the inspection procedure. While the auxiliary battery is connected, even if the power switch is off, the brake control system activates when the brake pedal is depressed or the door courtesy light switch is turned on. Therefore during servicing of the brake system components, do not depress the brake pedal and open/close the doors while the auxiliary battery is connected. The removal or installation of the actuator, master cylinder or stroke simulator as well as other procedures can cause the brake fluid level to drop below the fluid reservoir. If this happens when performing such work, be sure to remove the 2 motor relays until the brake line has been bled. HINT: If the pump motor is operated while there is air in the brake actuator hose, bleeding the air becomes difficult due to air in the actuator. The skid control ECU assembly may operate the stroke simulator and drive the pump motor even when the power switch is off. With the power switch off, the skid control ECU assembly can be operated for 2 minutes after operating the brake pedal. Removal of the ABS motor relay. Wait for 2 minutes after turning the power switch off, operating the brake pedal and closing the driver door before removing the relays. HINT: The skid control ECU assembly operates the pump motor just before the brake control system shuts down in order to prepare the system for the next time it is operated. If the ECU, brake actuator assembly, or a sensor has been removed and installed, it is necessary to check the system for problems after the parts have been reassembled. Check for DTCs using the Techstream, and also check that system functions and signals received by the ECU are normal using Test Mode.
3. DTC PRECAUTION Warnings for some DTCs cannot be cleared only by repairing the malfunctioning parts. If the warning is displayed even after repair work, the DTC should be cleared after turning the power switch off. NOTE: If a DTC for a malfunctioning part reappears after it was cleared, then it has been stored again.
4. CHASSIS DYNAMOMETER PRECAUTION Enter Inspection Mode to disable TRAC and VSC control when using a chassis dynamometer. Refer to «INSPECTION MODE PROCEDURE [03/2012 - ]»(ref-600412-S34816019962014022400000) . NOTE: Make sure that the slip indicator lights blink (Inspection Mode is activated). Secure the vehicle with a lock chain for safety. When performing procedures related to VSC OFF switch operation, make sure that the mode is VSC off mode.
5. BRAKE TESTER PRECAUTION When inspecting the brakes using the brake tester, the braking force of the rear wheels may be reduced. When the vehicle speed is 0 km/h (0 mph), the brake control system of the vehicle limits the rear brake fluid pressure to approximately 50% of the normal brake fluid pressure when driving the vehicle, in order to reduce energy consumption.
6. CAN COMMUNICATION SYSTEM PRECAUTIONS The CAN communication system is used for the data communication between the skid control ECU, the steering angle sensor, yaw rate sensor and other ECUs. If there are any problems in the CAN communication line, corresponding DTCs in the communication line are stored. If any CAN communication line DTCs are output, repair the malfunction in the communication line and troubleshoot the electronically controlled brake system when data communication is normal. In order to enable CAN communication, a specific type of wiring is used for the CAN communication lines. The wiring used for each communication line is a twisted pair of wires that have an equal length. A bypass wire should not be used, because the data being transmitted will be corrupted.

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CHECK FOR INTERMITTENT PROBLEMS [03/2012 - ]

1. CHECK FOR INTERMITTENT PROBLEMS HINT: A momentary interruption (open circuit) in the connectors and/or wire harnesses between the sensors and ECUs can be detected using the ECU Data List function of the Techstream. Turn the power switch off. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Follow the directions on the Techstream to display the Data List and select areas where momentary interruptions should be monitored. HINT: A momentary interruption (open circuit) cannot be detected for 3 seconds after the power switch is turned on (IG) (initial check). If the Error display remains displayed, check for continuity between the ECUs and the sensors, or between ECUs. The Error display on the Techstream will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition. ABS/VSC/TRAC Tester Display Measurement Item/Range Normal Condition Diagnostic Note FR Speed Open Front speed sensor RH open detection / Error or Normal Error: Momentary interruption Normal: Normal - FL Speed Open Front speed sensor LH open detection / Error or Normal Error: Momentary interruption Normal: Normal - RR Speed Open Rear speed sensor RH open detection / Error or Normal Error: Momentary interruption Normal: Normal - RL Speed Open Rear speed sensor LH open detection / Error or Normal Error: Momentary interruption Normal: Normal - Yaw Rate Open Yaw rate sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - Deceleration Open Acceleration sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - Steering Open Steering sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - Master Cylinder Open Master cylinder pressure sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - Master Cylinder2 Open Master cylinder pressure sensor 2 open detection / Error or Normal Error: Momentary interruption Normal: Normal - Stroke Open Stroke sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - FR Wheel Cylinder Open Front wheel cylinder pressure sensor RH open detection / Error or Normal Error: Momentary interruption Normal: Normal - FL Wheel Cylinder Open Front wheel cylinder pressure sensor LH open detection / Error or Normal Error: Momentary interruption Normal: Normal - RR Wheel Cylinder Open Rear wheel cylinder pressure sensor RH open detection / Error or Normal Error: Momentary interruption Normal: Normal - RL Wheel Cylinder Open Rear wheel cylinder pressure sensor LH open detection / Error or Normal Error: Momentary interruption Normal: Normal - Accumulator Open Accumulator pressure sensor open detection / Error or Normal Error: Momentary interruption Normal: Normal - HV Communication Open Hybrid vehicle communication open detection / Error or Normal Error: Momentary interruption Normal: Normal - While observing the screen, gently jiggle the connectors or wire harnesses between the ECUs and sensors, or between ECUs. OK Normal display appears. HINT: If the display changes, this indicates that there has been a momentary interruption (open circuit) in the connector and/or wire harness. In this case, repair or replace the connectors and/or wire harnesses as one of them is faulty.

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1. DESCRIPTION Perform initialization and calibration of the linear solenoid valve when the skid control ECU assembly, brake actuator assembly or brake pedal stroke sensor assembly is replaced. Follow the procedure to perform initialization. HINT: If there is a problem with the auxiliary battery (12 V) voltage, initialization and calibration of the linear solenoid valve cannot be completed normally. Make sure to check the auxiliary battery voltage before performing initialization and calibration of the linear solenoid valve. If the actuator's temperature is high, initialization and calibration of the linear solenoid valve may not be completed normally. If so, wait until the temperature decreases and then perform initialization and calibration of the linear solenoid valve. If the power switch is turned off, the brake pedal is depressed or vehicle speed signal is input while the linear solenoid valve offset learning is being performed, the learning will be canceled. Part to be Replaced Necessary Operation Skid control ECU assembly Initialization and calibration of the linear solenoid valve Brake actuator assembly Bleed air Clearing stored linear solenoid valve calibration data Initialization and calibration of the linear solenoid valve Brake pedal stroke sensor assembly Brake pedal Clearing stored linear solenoid valve calibration data Initialization and calibration of the linear solenoid valve
2. PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE (When Using the Techstream) Clear the stored linear solenoid valve calibration data. Turn the power switch off. Check that the steering wheel is centered. Check that the shift lever is in P. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Select the skid control ECU assembly to clear the linear solenoid valve calibration data using the Techstream. Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / Reset Memory. Perform initialization and calibration of the linear solenoid valve. Turn the power switch off. Check that the steering wheel is centered. Check that the shift lever is in P. Connect the Techstream to the DLC3. Turn the power switch on (IG) with the brake pedal released. NOTE: If the linear solenoid valve offset learning is performed without turning the power switch on (IG), the learning process may not be completed properly because of insufficient auxiliary battery voltage. When the linear solenoid valve offset learning is interrupted, or the learning process is performed with the shift lever not in P, DTC C1345 (Linear Solenoid Valve Offset Learning Undone) will be stored. Turn the Techstream on. Switch the skid control ECU assembly to the Test Mode using the Techstream. Enter the following menus: Chassis / ABS/VSC/TRAC / Utility / ECB* Utility / Linear Valve Offset. *: Electronically Controlled Brake System Leave the vehicle stationary without depressing the brake pedal for 2 minutes. Check that the interval between blinks of the brake warning light / yellow (minor malfunction) changes from 1 second to 0.25 seconds. HINT: The time needed to complete initialization and calibration of the linear solenoid valve varies depending on auxiliary battery voltage. The brake warning light / yellow (minor malfunction) blinks at 1 second intervals during initialization and calibration of the linear solenoid valve. After initialization and calibration are complete, the brake warning light / yellow (minor malfunction) changes to the Test Mode display and blinks at 0.25 second intervals. Check that DTC C1345 (Linear Solenoid Valve Offset Learning Undone) which indicates trouble with stroke sensor zero point learning is not output when the brake warning light / yellow (minor malfunction) changes to the Test Mode display upon initialization and calibration of the linear solenoid valve completion. Perform the zero point calibration of yaw rate and acceleration sensor. Refer to «CALIBRATION [03/2012 - ]»(ref-600441-S38783757642014022400000) . Enter the normal mode from the Test Mode following the Techstream directions. HINT: Refer to the Techstream operator's manual for further details.
3. PERFORM INITIALIZATION AND CALIBRATION OF LINEAR SOLENOID VALVE (When not Using the Techstream) Clear the stored linear solenoid valve calibration data. Turn the power switch off. Check that the steering wheel is centered. Check that the shift lever is in P. Turn the power switch on (IG) with the brake pedal released. Using SST, connect and disconnect terminals TS and CG of the DLC3 4 times or more within 8 seconds. SST: 09843-18040 TEXT IN ILLUSTRATION *a Front view of DLC3 Check that no codes other than ABS code 42, VSC code 45 and electronically controlled brake system code 48, 66, or 95 are stored in the diagnostic system. HINT: How to read DTCs: Diagnostic trouble codes are represented by the number of blinks of a warning light. For example, code 21 would be shown by 2 blinks, a pause of 1.5 seconds, and then 1 blink. If one code is detected: The light repeats the same code after a pause of 4 seconds. If multiple codes are detected: The light outputs one code after another with a 2.5-second pause between each code. When all codes have been output, there is a 4-second pause and then the light begins to output the codes again. The ABS warning, brake warning / yellow (minor malfunction) and slip indicator lights do not indicate a normal system code. Perform initialization and calibration of the linear solenoid valve. Turn the power switch off. Check that the steering wheel is centered. Check that the shift lever is in P. Using SST, connect terminals TS and CG of the DLC3. SST: 09843-18040 TEXT IN ILLUSTRATION *a Front view of DLC3 Turn the power switch on (IG) with the brake pedal released. NOTE: If the linear solenoid valve offset learning is performed without turning the power switch on (IG), the learning process may not be completed properly because of insufficient auxiliary battery voltage. When the linear solenoid valve offset learning is interrupted, or the learning process is performed with the shift lever not in P, DTC 66 (Linear Solenoid Valve Offset Learning Undone) will be stored. Leave the vehicle stationary without depressing the brake pedal for 2 minutes. Check that the interval between blinks of the brake warning light / yellow (minor malfunction) changes from 1 second to 0.25 seconds. HINT: The time needed to complete initialization and calibration of the linear solenoid valve varies depending on the auxiliary battery voltage. The brake warning light / yellow (minor malfunction) blinks at 1 second intervals during initialization and calibration of the linear solenoid valve. After initialization and calibration are complete, the brake warning light / yellow (minor malfunction) changes to the Test Mode display and blinks at 0.25 second intervals. Check that DTC 66 (Linear Solenoid Valve Offset Learning Undone) which indicates trouble with stroke sensor zero point learning is not output when the brake warning light / yellow (minor malfunction) changes to the Test Mode display upon initialization and calibration of the linear solenoid valve completion. Perform the zero point calibration of yaw rate and acceleration sensor. Refer to «CALIBRATION [03/2012 - ]»(ref-600441-S38783757642014022400000) . Turn the power switch off and disconnect SST from the DLC3.

FREEZE FRAME DATA [03/2012 - ]

1. FREEZE FRAME DATA/INFORMATION Whenever an ABS, VSC, or electronically controlled brake system DTC is detected, the skid control ECU assembly stores the current vehicle (sensor) state as Freeze Frame Data. The skid control ECU assembly stores the number of times (maximum: 31) the power switch has been turned from off to on (IG) since the last time the ABS was activated. For DTCs stored in the skid control ECU assembly, information (INF) codes that are contained in the Freeze Frame Data can be displayed on the Techstream. HINT: However, if the vehicle is stopped or at a low speed (7 km/h (4.3 mph) or less), or if a DTC is detected, the skid control ECU assembly will stop counting the number of times the power switch had been turned from off to on (IG). Freeze Frame Data at the time the ABS operates: The skid control ECU assembly stores and updates data whenever the ABS system operates. When the ECU stores data at the time a DTC is detected, the data stored during ABS operation is cleared. Freeze Frame Data at the time a DTC is detected: When the skid control ECU assembly stores data at the time a DTC is detected, no updates will be performed until the data is cleared.
2. CHECK FREEZE FRAME DATA AND INFORMATION Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes. According to the display on the Techstream, select the trouble code data display with Freeze Frame Data. Read the Freeze Frame Data recorded when the DTC was set. Read the information. Select the item that has an information (INF) code from the Freeze Frame Data screen. ABS/VSC/TRAC Tester Display Measurement Item/Range Normal Condition Diagnostic Note Detailed Freeze DTC Detailed code for Freeze Frame DTC / Min.: 0, Max.: 65535 - Number of information (INF) code output is displayed Elapsed Time after Freeze Trigger Elapsed time after freeze trigger / Min.: 0 msec, Max.: 500 msec - - Number of IG ON Number of operations of power switch on (IG) after storing Freeze Frame Data / 0 to 31 - - Elapsed Time Elapsed time after power switch on (IG) / Min.: 0 sec., Max.: 100661 sec. - - Buzzer Skid control buzzer / ON or OFF ON: Buzzer on OFF: Buzzer off - Stop Light SW Stop light switch / ON or OFF ON: Brake pedal depressed OFF: Brake pedal released - Parking Brake SW Parking brake status / ON or OFF ON: Parking brake applied OFF: Parking brake released - TRC(TRAC)/VSC OFF SW VSC OFF switch / ON or OFF ON: Switch on OFF: Switch off - Reservoir Warning SW Brake fluid level warning switch / ON or OFF ON: Reservoir level low OFF: Reservoir level normal - Shift Lever Position Shift lever position information / Fail, 1st-6th/B, D/M, P, N or R Actual shift lever position - Operated System Operated system status / ABS, VSC, TRAC, BA, PB, PBA, HAB, HA-CTRL, TSC, Fail, Non or Sys - ABS: ABS activated VSC: VSC activated TRAC: TRAC activated BA: BA activated PB: PB activated PBA: PBA activated Fail: Fail safe mode activated Non: No system activated Sys: System prohibited Master Cylinder Sensor Master cylinder pressure sensor 1 / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed M/C Sensor Grade Master cylinder pressure sensor change / Min.: -30 MPa/s, Max.: 225 MPa/s When brake pedal is released or pedal held at constant position: 0 MPa/s When brake pedal is being depressed: Changes in proportion with pedal movement speed Master Cylinder Sensor2 Master cylinder pressure sensor 2 / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed Stroke Sensor Brake pedal stroke sensor 1 / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.8 to 1.2 V Reading increases when brake pedal is depressed Stroke Sensor2 Brake pedal stroke sensor 2 / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 3.8 to 4.2 V Reading decreases when brake pedal is depressed Accumulator Sensor Accumulator pressure sensor / Min.: 0.00 V, Max.: 5.00 V Specified value: 2.6 to 3.8 V When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator Yaw Rate Sensor Yaw rate sensor / Min.: -128 °/s, Max.: 127 °/s Vehicle stopped: 0 °/s Turning right: -128 to 0 °/s Turning left: 0 to 127 °/s - FR W/C Sensor Front wheel cylinder pressure sensor RH / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed FL W/C Sensor Front wheel cylinder pressure sensor LH / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed RR W/C Sensor Rear wheel cylinder pressure sensor RH / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed RL W/C Sensor Rear wheel cylinder pressure sensor LH / Min.: 0.00 V, Max.: 5.00 V When brake pedal released: 0.3 to 0.7 V Reading increases when brake pedal is depressed Lateral G Lateral G / Min.: -25.10 m/s 2 , Max.: 24.90 m/s 2 - During turning: Changes in proportion with acceleration Forward and Rearward G Forward and backward G / Min.: -25.10 m/s 2 , Max.: 24.90 m/s 2 - During acceleration/deceleration: Changes in proportion with acceleration FR Wheel Speed Front wheel speed sensor RH / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations FL Wheel Speed Front wheel speed sensor LH / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations RR Wheel Speed Rear wheel speed sensor RH / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations RL Wheel Speed Rear wheel speed sensor LH / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations Vehicle Speed Maximum wheel speed sensor / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations Accelerator Opening Angle % Accelerator pedal depressed amount / Min.: 0.0%, Max.: 128.0% When the accelerator pedal released: 0% During accelerator pedal operation: Changes in proportion with the pedal movement ECB*1 Motor Relay ABS motor relay 1 / ON or OFF ON: Relay on OFF: Relay off - ECB*1 Motor Relay2 ABS motor relay 2 / ON or OFF ON: Relay on OFF: Relay off - ECB*1 Main Relay ABS main relay 1 / ON or OFF ON: Relay on OFF: Relay off - ECB*1 Main Relay2 ABS main relay 2 / ON or OFF ON: Relay on OFF: Relay off - ECB*1 Solenoid (SMC1) Master cut solenoid (SMC1) / ON or OFF ON: Solenoid on OFF: Solenoid off - ECB*1 Solenoid (SMC2) Master cut solenoid (SMC2) / ON or OFF ON: Solenoid on OFF: Solenoid off - Capacitor Mode Capacitor mode / ON or OFF ON: Mode on OFF: Mode off - IG1 Voltage Value IG1 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage IG2 Voltage Value IG2 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage BS1 Voltage Value BS1 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage BS2 Voltage Value BS2 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage VM1 Voltage Value VM1 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage VM2 Voltage Value VM2 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage +B1 Voltage Value +B1 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage +B2 Voltage Value +B2 voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage Motor Relay Voltage Value Motor relay voltage value / Min.: 0.00 V, Max.: 20.00 V - Changes in proportion to auxiliary battery voltage SLAFR Solenoid Current Linear solenoid (FRA) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLAFL Solenoid Current Linear solenoid (FLA) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLARR Solenoid Current Linear solenoid (RRA) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLARL Solenoid Current Linear solenoid (RLA) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLRFR Solenoid Current Linear solenoid (FRR) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLRFL Solenoid Current Linear solenoid (FLR) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLRRR Solenoid Current Linear solenoid (RRR) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - SLRRL Solenoid Current Linear solenoid (RLR) current / Min.: 0.00 A, Max.: 1.50 A When brake pedal released: 0 A - FR Target Oil Pressure Front wheel RH target hydraulic pressure / Min.: 0.00 Mpa, Max.: 20.00 Mpa Changes according to the target wheel cylinder hydraulic pressure - FL Target Oil Pressure Front wheel LH target hydraulic pressure / Min.: 0.00 Mpa, Max.: 20.00 Mpa Changes according to the target wheel cylinder hydraulic pressure - RR Target Oil Pressure Rear wheel RH target hydraulic pressure / Min.: 0.00 Mpa, Max.: 20.00 Mpa Changes according to the target wheel cylinder hydraulic pressure - RL Target Oil Pressure Rear wheel LH target hydraulic pressure / Min.: 0.00 Mpa, Max.: 20.00 Mpa Changes according to the target wheel cylinder hydraulic pressure - Inspection Mode Inspection mode / Other or Inspect Other: Normal mode Inspect: Inspection mode - Steering Angle Sensor Steering sensor / Min.: - 3276.8°, Max.: 3276.7° Left turn: Increase Right turn: Decrease - VCM1 Voltage Value VCM1 voltage value / Min.: 0.00 V, Max.: 10.00 V Specified value: 4.8 to 5.2 V - VCM2 Voltage Value VCM2 voltage value / Min.: 0.00 V, Max.: 10.00 V Specified value: 4.8 to 5.2 V - TRAC/VSC Off Mode TRAC/VSC off mode / Normal, TRC OFF or VSC OFF Normal: Normal mode TRC OFF: TRAC off mode VSC OFF: VSC off mode - Brake Hold Control Brake hold control status / OFF, Hold, Release, EPB*2 OFF: Brake hold control not operating Hold: Brake hold operating during brake hold control Release: Brake hold released during brake hold control EPB*2: Electric parking brake operating during brake hold control - Voltage of Stroke Sensor Voltage of brake pedal stroke sensor assembly 1 / Min.: -2.50 V, Max.: 2.49 V - - Voltage of Stroke Sensor2 Voltage of brake pedal stroke sensor assembly 2 / Min.: -2.50 V, Max.: 2.49 V - - *1: Electronically Controlled Brake System *2: Electric Parking Brake System
3. CLEAR FREEZE FRAME DATA AND INFORMATION NOTE: Clearing the DTCs will also clear the Freeze Frame Data and information (INF) codes. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Clear the DTCs and Freeze Frame Data. Refer to «DTC CHECK / CLEAR [03/2012 - ]»(ref-600441-S41685570292014022400000) .

FAIL-SAFE CHART [03/2012 - ]

1. FAIL-SAFE FUNCTION OF CONTROL SYSTEM If a malfunction occurs in the skid control ECU assembly, sensor signal, or actuator, the remaining functioning components will maintain brake control. If a malfunction occurs in the brake control system, the skid control ECU assembly turns the warning light on, and prohibits ABS, BA VSC and brake hold operations. Item Operation Malfunction in the ABS ABS, BA, TRAC and VSC control prohibited Brake hold control prohibited* Malfunction in the BA system ABS, BA, TRAC and VSC control prohibited Brake hold control prohibited* Malfunction in the EBD system ABS, EBD, BA, TRAC and VSC control prohibited Brake hold control prohibited* Malfunction in the TRAC system ABS, BA, TRAC and VSC control prohibited Brake hold control prohibited* Malfunction in the VSC system ABS, BA, TRAC and VSC control prohibited Brake hold control prohibited* *: Only during brake hold control A power back-up unit is built in as an additional power source to supply stable power to the system. The skid control ECU assembly prohibits VSC control in order to protect the system and prevent improper operation when related systems (hybrid control system) are malfunctioning. Brake hold control prohibits brake hold operation in order to protect the system and prevent improper operation when the electronically controlled brake system, electric parking brake system or hybrid control system is malfunctioning.
2. FAIL-SAFE FUNCTION OF HYDRAULIC SYSTEM When a malfunction occurs, the skid control ECU prohibits operation of parts determined to be malfunctioning and continues brake power assist control using the properly functioning systems. HINT: The system of wheels for which brake power assist is prohibited due to the fail-safe function loses brake power assist or braking ability. If the brake power assist becomes prohibited, the feeling of the brake pedal may change. If brake power assist becomes prohibited for all wheels, the 2 front wheels lose brake power assist. If the brake control is stopped under conditions such as when a malfunction occurs with a hydraulic pressure source, the pressure generated in the master cylinder by the driver is applied to the front wheel cylinders to ensure braking force. If the regenerative brake alone does not operate under conditions such as a communication error with the power management control ECU, control is switched so that all braking force is generated with hydraulic braking pressure. Item Operation Skid control ECU assembly malfunction Normally operating parts will control brake and generated braking force Hydraulic pressure controlling parts malfunction Normally operating parts will control brake and generated braking force Power supply parts (Hydraulic pressure source) malfunction Braking force solely generated by the driver