Section 300 (Abs W/EBD & BA & TRAC & VSC System - Diagnosis): Pre-Check
- DIAGNOSIS SYSTEM
- Check the warning lights.
- Release parking brake pedal.NOTE: When releasing the parking brake, set the chocks to hold the vehicle for safety.
HINT:
When the parking brake is applied or the level of the brake fluid is low, the BRAKE warning light comes on.
- When the ignition switch is turned to the ON position, check that the ABS warning light, BRAKE warning light, VSC warning light, TRAC OFF indicator light and SLIP indicator light remain on for approx. 3 seconds.
- Release parking brake pedal.
HINT:
- If the ECU has any stored DTCs, the ABS warning light, VSC warning light and TRAC OFF indicator light come on.
- If the indicator does not come on, inspect if the bulb is blown out, and also the wire harness between the skid control ECU and the combination meter.
- If the indicator remains on, proceed to troubleshooting for the light circuit below.
- Check the warning lights.
- DTC CHECK/CLEAR (USING SST CHECK WIRE)
- Check DTCs.
- Using SST, connect terminals TC and CG of the DLC3.
SST 09843-18040
- Turn the ignition switch to the ON position.
- Read the DTC from the ABS warning light or VSC warning light on the combination meter.
HINT:
- If 2 or more malfunctions are detected at the same time, the lowest numbered code will be displayed first.
- If no code appears, inspect the diagnostic circuit, ABS warning light circuit or VSC warning light circuit.
- As an example, the blinking patterns for a normal system code and codes 11 and 21 are shown in Fig 5 .
- Codes are explained in the code table on DIAGNOSTIC TROUBLE CODE CHART .
- After completing the check, disconnect terminals TC and CG of the DLC3, and turn off the display.
- Using SST, connect terminals TC and CG of the DLC3.
- Clear DTCs.
- Using SST, connect terminals TC and CG of the DLC3.
SST 09843-18040
- Turn the ignition switch to the ON position.
- Clear the DTCs stored in the ECU by depressing the brake pedal 8 or more times within 5 sec.
- Check that the ABS warning light and VSC warning light show normal blinking patterns.
- Remove the SST from the DLC3.
SST 09843-18040
- Using SST, connect terminals TC and CG of the DLC3.
- Check DTCs.
- DTC CHECK/CLEAR (USING HAND-HELD TESTER)
- Check DTCs.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to the ON position.
- Read the DTCs following the prompts on the tester screen.
HINT:
Refer to the hand-held tester operator's manual for further details.
- Clear the DTCs.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to the ON position.
- Operate the hand-held tester to erase the code
HINT:
Refer to the hand-held tester operator's manual for further details.
- Check DTCs.
- DATA LIST
HINT:
According to the DATA LIST displayed on the hand-held tester, you can read the value and status of the switch, sensor, actuator and so on without parts removal. Reading the DATA LIST as the first step of troubleshooting is one of the methods to shorten labor time.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch ON.
- From the display on the tester, read the "DATA LIST".
- ACTIVE TEST
HINT:
Performing the ACTIVE TEST using the hand-held tester allows the relay and actuator, etc. to operate without removing any parts. Performing the ACTIVE TEST as the first step of troubleshooting is one of the methods to shorten labor time.
It is possible to display the DATA LIST during the ACTIVE TEST.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to the ON position.
- According to the display on the tester, perform the "ACTIVE TEST".
HINT:
Ignition switch must be turned to the ON position to proceed to the ACTIVE TEST using the hand-held tester.
- FREEZE FRAME DATA
HINT:
- Whenever a DTC is detected or the ABS operates, the skid control ECU stores the current vehicle (sensor) state as freeze frame data.
- The skid control ECU stores the number of times (maximum: 31) the ignition switch has been turned from off to the ON position since the last time ABS was activated. However, if the vehicle was stopped or at low speed (4.3 mph (7 km/h) or less), or if a DTC is detected, the skid control ECU will not count the number since then.
- Freeze frame data at the time the ABS operates:
The skid control ECU stores and updates data whenever the ABS system operates.
When the ECU stores data at the time a DTC is detected, the data stored when the ABS operated is erased.
- Freeze frame data at the time a DTC is detected:
When the skid control ECU stores data at the time a DTC is detected, no updates will be performed until the data is cleared.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to the ON position.
- From the display on the tester, select the "FREEZE FRAME DATA".
- SENSOR SIGNAL CHECK (TEST MODE) (USING SST CHECK WIRE) NOTE: After replacing the yaw rate sensor (deceleration sensor) and/or brake actuator assembly (skid control ECU), perform zero point calibration of the yaw rate sensor and deceleration sensor. (See step 9.)
HINT:
- If the ignition switch is turned from ON to the ACC or LOCK position during test mode, DTC of sensor check function will be erased.
- During test mode, ECU records all DTCs of sensor check functions. By performing sensor signal check, the codes are erased if normality is confirmed. The codes left over are the codes where an abnormality was found.
- Procedures for test mode:
- Turn the ignition switch off.
- Check that the steering wheel is in the straight-ahead position and shift the shift lever to the P position.
- Using SST, connect terminals TS and CG of the DLC3.
SST 09843-18040
- Turn the ignition switch to the ON position.
- Check that the ABS warning light and VSC warning light blink.
HINT:
If the ABS warning light and VSC warning light do not blink, inspect the ABS warning light circuit, VSC warning light and TS terminal circuit.
- Check the master cylinder pressure sensor:
- Leave the vehicle in a stationary condition and the brake pedal in a free condition for 1 second or more, and quickly depress the brake pedal with a force of 98 N (10 kgf) or more for 1 second or more.
HINT:
- At this time, the ABS warning light remains on for 3 seconds.
- While the ABS warning light remains on, continue to depress the brake pedal with a force of 98N (10 kgf) or more.
- The ABS warning light comes on for 3 seconds every time the above brake pedal operation is performed.
- If master cylinder pressure sensor check can not be completed, do not depress the brake pedal frequently. It may further reduce negative pressure and make the sensor check difficult to complete.
- If the negative pressure is insufficient, master cylinder pressure sensor check may not be completed. In this case, idle the engine to get enough negative pressure.
- If the brake pedal is depressed while engine is stopped, negative pressure may become insufficient and the BRL may come on. (It runs the motor and performs incorrect control.)
- Check the yaw rate sensor:
- Shift the shift lever to the D position and drive the vehicle at a speed of approx. 3 mph (5 km/h), turn the steering wheel either to the left or right 90° or more, and maintain a 180° circular drive for the vehicle.
- Stop the vehicle and shift the shift lever to the P position, check that the skid control buzzer sounds for 3 sec.
NOTE: Deceleration sensor check should be completed before performing speed sensor check.HINT:
- If the skid control buzzer sounds, the sensor check is completed normally.
- If the skid control buzzer does not sound, check the skid control buzzer circuit (see SKID CONTROL BUZZER CIRCUIT ), then perform the sensor check again. If the skid control buzzer still does not sound, there is a malfunction in the VSC sensor, so check for DTCs.
- Drive the vehicle in a 180° circle. At the end of the turn, ensure that the vehicle is exactly 180° within a tolerance of +/- 5°, and facing the other direction from its original start position.
- Do not spin the wheels.
- Check the speed sensor signal:
- Drive the vehicle straight forward at a speed of 28 mph (45 km/h) or higher for several seconds and check that the ABS warning light goes off.
HINT:
The sensor check may not be completed if the vehicle has its wheels spun or its steering wheel turned during this check.
- Stop the vehicle.NOTE:
- Before performing speed sensor check, complete master cylinder pressure sensor and deceleration sensor checks.
- Speed sensor check may not be completed if speed sensor check is started while turning the steering wheel or spinning the wheels.
- After the ABS warning light goes off, if the vehicle speed exceeds 50 mph (80 km/h), sensor check code is stored again. Decelerate or stop the vehicle before the speed reaches 50 mph (80 km/h).
- If sensor check has not been completed, the ABS warning light blinks while driving and ABS system does not operate.
HINT:
When sensor check has been completed, the ABS warning light goes off while driving and blinks in the test mode pattern while standing.
- Using SST, connect terminals TC and CG of the DLC3.
SST 09843-18040
- Read the number of blinks of the ABS warning light and VSC warning light.
HINT:
- See the list of DTC. (see DIAGNOSTIC TROUBLE CODE CHART )
- If every sensor is normal, the normal blinking patterns are output. (A cycle of 0.25 seconds ON and 0.25 seconds OFF is repeated.)
- If 2 or more malfunctions are detected at the same time, the lowest numbered code will be displayed first.
- After performing the check, disconnect the SST from terminals TS and CG, TC and CG of the DLC3 and turn the ignition switch off.
- Drive the vehicle straight forward at a speed of 28 mph (45 km/h) or higher for several seconds and check that the ABS warning light goes off.
- SENSOR SIGNAL CHECK (TEST MODE) (USING HAND-HELD TESTER) NOTE: After replacing the yaw rate sensor (deceleration sensor) and/or brake actuator assembly (skid control ECU), perform zero point calibration of the yaw rate sensor and deceleration sensor. (See step 10.)
HINT:
- If the ignition switch is turned from ON to the ACC or LOCK position during test mode, DTC of sensor check function will be erased.
- During test mode, ECU records all DTC of sensor check function. By performing sensor signal check, the codes are erased if normality is confirmed. The codes left over are the codes where an abnormality was found.
- Procedures for test mode:
- Turn the ignition switch off.
- Check that the shift lever position is in the P position.
- Connect the hand-held tester to the DLC3.
- Put the hand-held tester in test mode.
- Check that the ABS warning light and VSC warning light blink.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
HINT:
If the ABS warning light and VSC warning light do not blink, inspect the ABS warning light circuit and VSC warning light circuit.
- Check the master cylinder pressure sensor:
- Leave the vehicle in a stationary condition and the brake pedal in a free condition for 1 second or more and quickly depress the brake pedal with a force of 98 N (10 kgf, 22 lbf) or more for 1 second or more.
HINT:
At this time, the ABS warning light remains on for 3 seconds.
- Check the yaw rate sensor:
- Shift the shift lever to the D position and drive the vehicle at a speed of approx. 3 mph (5 km/h), and maintain a 180° circular drive for the vehicle.
- Stop the vehicle and shift the shift lever to the P position, then check that the skid control buzzer sounds for 3 seconds.
HINT:
- If the skid control buzzer sounds, the sensor check is completed normally.
- If the skid control buzzer does not sound, check the skid control buzzer circuit (see SKID CONTROL BUZZER CIRCUIT ), then perform the sensor check again. If the skid control buzzer still does not sound, there is a malfunction in the VSC sensor, so check for DTC.
- Drive the vehicle in a 180° circle. At the end of the turn, ensure that the vehicle is exactly 180° within a tolerance of +/- 5°, and facing the other direction from its original start position.
- Do not spin the wheels.
- Check the speed sensor:
- Drive the vehicle straight forward at the speed of 28 mph (45 km/h) or higher for several seconds and check that the ABS warning light goes off.
HINT:
The sensor check may not be completed if the vehicle has its wheels spun or its steering wheel turned during this check.
- Stop the vehicle.
- Drive the vehicle straight forward at the speed of 28 mph (45 km/h) or higher for several seconds and check that the ABS warning light goes off.
- Read the DTC following the tester screen.
HINT:
Refer to the hand-held tester operator's manual for further details.
- IF NECESSARY, PERFORM ZERO POINT CALIBRATION OF YAW RATE SENSOR AND/OR BRAKE ACTUATOR ASSY (USING SST CHECK WIRE) NOTE:
- While obtaining the zero point, do not tilt, move or shake the vehicle but keep it in a stationary condition. (Do not start the engine.)
- Be sure to perform the operation on a level surface (within an inclination of 1%).
- Check that the steering wheel is in the straight-ahead position and shift the shift lever to the P position.
- Clear the zero point calibration:
HINT:
After replacing the yaw rate sensor, make sure to clear zero point calibration data in the skid control ECU and perform zero point calibration.
- Turn the ignition switch to the ON position.
- Using SST, connect and disconnect terminals TS and CG of the DLC3 4 times or more within 8 seconds.
SST 09843-18040
- Remove the SST from the terminals of the DLC3.
- Obtain the zero point calibration:
- Turn the ignition switch off.
- Using SST, connect terminals TS and CG of the DLC3.
SST 09843-18040
- Turn the ignition switch to the ON position.
- Keep the vehicle in a stationary condition on a level surface for 2 seconds or more.
- Check that the VSC warning light blinks.
HINT:
If the VSC warning light does not blink, perform the zero point calibration again.
- Remove the SST from the terminals of the DLC3.
SST 09843-18040
- Turn the ignition switch off.
- IF NECESSARY, PERFORM ZERO POINT CALIBRATION OF YAW RATE SENSOR AND/OR BRAKE ACTUATOR ASSY (USING HAND-HELD TESTER) NOTE:
- While obtaining the zero point, do not tilt, move or shake the vehicle but keep it in a stationary condition. (Do not start the engine.)
- Be sure to perform the operation on a level surface (within an inclination of 1 %).
- Check that the steering wheel is in the straight-ahead position and shift the shift lever to the P position.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to the ON position.
- Operate the hand-held tester to clear zero point calibration.
HINT:
After replacing the yaw rate sensor, make sure to clear zero point calibration data in the skid control ECU and perform zero point calibration.
- Operate the hand-held tester to test mode.
- Obtain zero point of the yaw rate sensor and deceleration sensor:
- Keep the vehicle in a stationary condition on a level surface for 2 seconds or more.
- Check that the VSC warning light blinks.
HINT:
If the VSC warning light does not blink, perform the zero point calibration again.
- Turn the ignition switch off.