Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Description & Operation
The primary purpose of the Brake Assist system is to provide an auxiliary brake force assist to the driver who cannot generate a large brake force during emergency braking, thus maximizing the vehicle's brake performance.
The ABS (Anti-Lock Brake System) helps to prevent the tires from locking up, thereby ensuring vehicle performance and handling ability.
The EBD (Electronic Brake force Distribution) system distributes optimal breaking force to the front and rear tires in accordance with driving conditions. Furthermore, braking force is distributed to the left and right wheels during braking when cornering to ensure vehicle performance and superior braking power.
The TRAC system helps prevent the drive wheels from slipping if the driver presses the accelerator pedal excessively when starting off or accelerating on a slippery surface.
The VSC system helps prevent the vehicle from slipping sideways as a result of strong front wheel skid or rear wheel skid during cornering.
When trouble shooting is conducted for Multiplex OBD (M-OBD) vehicles, the only difference from the usual trouble shooting procedure is the LEXUS hand-held tester is to be connected to read off various data output from the vehicle's skid control ECU. The skid control ECU records the corresponding DTC when the computer detects a malfunction in the computer itself or its circuit. To check DTC, connect the hand-held tester to DLC3 on the vehicle. The hand-held tester enables you to erase DTC and activate the several solenoids and actuators, and check freeze frame data and various forms on skid control data. See Fig 1.
For component locations see Fig 2.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.