Diagnostics Lexus

The engine control unit is a key component for the proper operation of the internal combustion engine. It manages combustion processes, ensures optimal performance, and maintains compliance with emission standards. The ECU responds to driver inputs and current operating conditions through numerous sensors and actuators.
Using diagnostics, it is possible to read and clear fault codes, monitor live data (e.g. fuel pressure, temperatures, engine speed), perform actuator tests (injectors, ignition coils, EGR), initiate diesel particulate filter regeneration, or carry out adaptations after component replacement.

This control unit manages the vehicle’s braking safety systems such as ABS, stability control (ESP), and hill-hold functions. It monitors the condition of individual wheels, braking system activity, and stability interventions during driving.
Diagnostics allow reading of fault codes, viewing sensor data (wheel speed, brake system pressure, pedal position), performing actuator tests, carrying out guided bleeding procedures, and other related functions.

The Body Control Module manages the vehicle’s comfort and auxiliary functions such as lighting, wipers, locking, turn signals, alarm, and remote control. It acts as a central hub for numerous sensors and switches.
Diagnostics allow configuration of functions (e.g. automatic wipers, coming/leaving home), testing of output signals (e.g. relay activation), reading sensor data, coding of new components, and real-time monitoring of input and output states.

This control unit is responsible for activating airbags and seatbelt pretensioners in the event of a collision. It monitors signals from crash sensors and determines when to deploy the protective systems.
Using diagnostics, it is possible to read the event memory (e.g. crash data), check individual circuits (resistance values, open circuits, short circuits), deactivate the passenger airbag, verify seatbelt pretensioner connections, and for certain types, clear crash data or register new components.

This unit manages the operation of automatic or automated transmissions. It determines when and how to shift, how to control the clutch, and the hydraulic system pressure. It responds to engine load, driving style, and driver inputs.
Diagnostics offer data reading (e.g. oil temperature, clutch status, pressure), shift adaptations, value resets after transmission replacement, testing of solenoid valves and sensors, and other functions.

The climate control unit ensures thermal comfort and regulates the vehicle’s interior environment. It controls the fan, directional flaps, compressor, and monitors temperature and humidity sensors.
Diagnostics allow testing of flap actuators, monitoring sensor status (e.g. evaporator temperature, outside temperature), reading refrigerant pressure, calibrating flap end positions, and evaluating compressor status or overall HVAC system performance.

The electronic parking brake (EPB) replaces the traditional handbrake with a motor controlled by the control unit. It enhances comfort and safety, as it can be integrated with the hill-start assist system.
Diagnostics allow activation and release of the brake in service mode (e.g. brake pad replacement), testing of the brake motor, monitoring of the actuator status, and performing calibrations after component replacement.

The instrument cluster displays essential operational information such as speed, engine RPM, fuel level, fault messages, and service intervals. It is often connected to the vehicle’s central network and serves as the user interface.
Diagnostics allow testing of needles and displays, setting service intervals, configuring displayed information, coding after unit replacement, and reading faults related to the display or communication with other control units.

This unit provides parking support using sensors and cameras, and in some cases semi-automatic steering. It assists with obstacle detection, calculating available space, and guiding the vehicle.
Diagnostics allow camera calibration, reading sensor values, testing display and alerts, configuring warning methods, and adapting the system after component replacement.

This system enhances safety by monitoring pressure and temperature in each wheel. TPMS can be direct (with sensors in the wheels) or indirect (using the ABS system).
Diagnostics allow sensor pairing, system reset after tire replacement, reading fault codes, monitoring pressure and temperature values, testing communication with individual sensors, and checking sensor battery status.

Each door may have a separate control unit that manages windows, locks, mirrors, lighting, and is linked to functions such as keyless entry or child lock.
Diagnostics allow testing of motor functions, button controls, lock feedback, reading the status of limit switches, and configuring comfort features (e.g. window auto-close when locking).

This unit protects against unauthorized vehicle start. It verifies the key code and allows engine start only upon correct verification.
Diagnostics allow checking synchronization with the ECU, reading communication faults, verifying the ignition ring antenna, and performing functional tests of key reading.

The electric power steering system adjusts the force required to turn the steering wheel. It responds to vehicle speed and axle load.
Diagnostics allow monitoring of the torque applied to the steering wheel, voltage and current of the power steering motor, calibration of the steering angle, testing of mechanical components, and reading faults such as overheating or system overload.

These units control exterior and interior lighting, including advanced functions such as adaptive lighting, cornering lights, and matrix LED.
Diagnostics allow testing of individual lighting circuits, configuration of functions (e.g. daytime running lights, interior lighting), headlight calibration, reading fault codes, and coding after replacement of the lighting module.

This unit manages multimedia, navigation, connectivity, and communication with the driver and passengers.
Diagnostics allow system reset or update, monitoring the status of connected devices (USB, Bluetooth), testing speakers and displays, checking for player or connectivity module faults, and modifying configurations according to vehicle equipment.

This unit provides connectivity between control units on different networks (CAN, LIN, FlexRay, etc.) and enables their mutual communication.
Diagnostics via the gateway allow access to other control units, monitoring of data flows, identification of overloaded or non-functional network branches, network configuration updates, coding of new units, and detection of communication faults.