Pre-Collision System (Diagnostic Codes & Circuit Tests): Overview Lexus ES XV60

DESCRIPTION

The seat belt control ECU receives information from the driving support ECU assembly using CAN communication and tightens the seat belt by operating the motor in the front seat outer belt assembly RH.

Scheme 189

Refer to DTC B2000. Refer to DESCRIPTION .

Refer to DTC B2000. Refer to DESCRIPTION .

The seat belt control ECU receives information from the driving support ECU assembly using CAN communication and tightens the seat belt by operating the motor in the front seat outer belt assembly LH.

Scheme 190

Refer to DTC B2005. Refer to DESCRIPTION .

Refer to DTC B2005. Refer to DESCRIPTION .

The DTCs above are stored during seat belt control ECU self-diagnosis.

HINT

1. When DTC B2015 or B2016 is detected, DTCs B2026 and B2027 will not be detected.
2. When DTC B2020 or B2021 is detected, DTCs B2031 and B2032 will not be detected.

If the seat belt control ECU judges that there is a malfunction in its internal circuit as a result of self-diagnosis, or if the power source voltage (+B) is not input to the seat belt control ECU, this DTC will be stored.

Scheme 191

This DTC is stored when a malfunction in the VSC system is detected. This circuit consists of the brake actuator assembly (skid control ECU) and seat belt control ECU. Signals are sent from the brake actuator assembly (skid control ECU) using CAN communication.

The seat belt control ECU is connected to the main body ECU (multiplex network body ECU) using CAN communication.

The seat belt control ECU receives vehicle model information from the main body ECU (multiplex network body ECU) and determines whether the seat belt buckle switch information is for the driver seat or the passenger seat.

DTC B2064 is stored when CAN communication with the main body ECU (multiplex network body ECU) is normal and communication is available, but the steering wheel position information is not set or varies.

These DTCs are stored when a malfunction is detected in the driver seat buckle switch circuit or passenger seat buckle switch circuit.

Scheme 192

This DTC is stored when CAN communication between the driving support ECU assembly and brake actuator assembly (skid control ECU) is interrupted.

This circuit consists of the driving support ECU assembly, brake actuator assembly (skid control ECU) and seat belt control ECU. DTC B2085 is stored when the seat belt control ECU detects an interruption in CAN communication between the driving support ECU assembly and brake actuator assembly (skid control ECU).

The seat belt control ECU receives information from the driving support ECU assembly and brake actuator assembly (skid control ECU) via CAN communication, and tightens the seat belts by operating the motor inside each front seat outer belt assembly.

When the driving support ECU assembly detects a malfunction in the dynamic radar cruise control system and pre-collision system, the malfunction information is sent to the seat belt control ECU, which stores this DTC.

When DTC B2090 is stored, other DTCs are also stored by the driving support ECU assembly (dynamic radar cruise control system and pre-collision system).

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle.

Based on this information, the driving support ECU assembly calculates the risk of a crash and operates the pre-collision system when it determines that the risk is high.

When a new driving support ECU assembly is installed, it receives vehicle specification information (destination, steering wheel position, 2WD or 4WD information, etc.) from the main body ECU (multiplex network body ECU) and memorizes the information.

DTC C1A02 is stored when the driving support ECU assembly receives the vehicle specification information from the main body ECU (multiplex network body ECU) but cannot record it.

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle.

Based on this information, the driving support ECU assembly sends pre-collision control operation signals.

When the millimeter wave radar sensor assembly is replaced with a new one, it acquires the country specification information from the driving support ECU assembly. Also, when the driving support ECU assembly is replaced with a new one, it receives country specification information from the main body ECU (multiplex network body ECU). When country specification information in the millimeter wave radar sensor assembly, driving support ECU and/or main body ECU do not match, DTC C1A0A is stored.

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle.

Based on this information, the driving support ECU assembly sends pre-collision control operation signals.

When the driving support ECU assembly receives information that there is a malfunction in the millimeter wave radar sensor assembly, DTC C1A10 is stored.

The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle.

Based on this information, the driving support ECU assembly sends pre-collision control operation signals.

When the vehicle is determined to be driving in a straight line or on a gradual curve based on signals from the yaw rate sensor etc., the millimeter wave radar sensor assembly performs self diagnosis to check if the sensor beam axis has deviated from the vehicle movement direction. When the millimeter wave radar sensor assembly beam axis has deviated, the driving support ECU assembly detects this, and stores DTC C1A11.

After installing a new millimeter wave radar sensor assembly, if sensor beam axis adjustment is not performed, DTC C1A14 is stored.

The brake actuator assembly (skid control ECU) receives vehicle stability control system signals from the airbag sensor assembly (yaw rate sensor) and sends the signals to the driving support ECU assembly and network gateway ECU. If the brake actuator assembly (skid control ECU) detects that the airbag sensor assembly (yaw rate sensor) is malfunctioning, the brake actuator assembly (skid control ECU) sends a malfunction signal to the driving support ECU assembly, and the driving support ECU assembly stores DTC C1A46. Also, when DTC C1A46 is stored, the brake actuator assembly (skid control ECU) stores DTC C1234 at the same time.

The brake actuator assembly (skid control ECU) receives steering rotation angle information from the steering angle sensor, and sends the information to the driving support ECU assembly via CAN communication.

If the brake actuator assembly (skid control ECU) detects a malfunction of the steering angle sensor, it sends a malfunction signal to the driving support ECU assembly and stores a DTC.

Based on pre-collision control, the driving support ECU assembly provides warnings to the driver. The driving support ECU assembly does this by sending a request signal to the brake actuator assembly (skid control ECU) to sound the skid control buzzer.

When the brake actuator assembly (skid control ECU) detects a malfunction in the skid control buzzer circuit, a malfunction signal is sent to the driving support ECU assembly, and this DTC is stored. Although the brake actuator assembly (skid control ECU) sends a malfunction signal to the driving support ECU assembly, the vehicle stability control system does not store a relevant malfunction detection DTC.

The stop light switch assembly sends a brake pedal operation signal to the driving support ECU assembly. Based on the signal, the driving support ECU assembly detects the operation of the brake pedal.

Scheme 193

When the driving support ECU receives an VSC system malfunction signal from the skid control ECU via the CAN communication line, DTC C1A50 is stored.

1. The driving support ECU assembly uses the millimeter wave radar sensor assembly to detect obstacles in front of the vehicle. Based on this information, the driving support ECU assembly sends pre-collision control operation signals. These DTCs are stored when a communication malfunction occurs between the sensors and ECUs that detect crashes, or between ECUs that perform the pre-collision control.

1. The driving support ECU assembly sends vehicle speed and vehicle condition information to the millimeter wave radar sensor assembly. The millimeter wave radar sensor assembly then sends information on the presence, distance, and relative speed of objects ahead to the driving support ECU assembly. The driving support ECU assembly sends this information to the ECM and performs pre-collision safety system operation (DTC U1104). DTC No. DTC Detection Condition Trouble Area U0125 When the engine switch is on (IG), a communication error between the airbag sensor assembly (yaw rate sensor) and the driving support ECU is detected for approximately 1 second. Airbag sensor assembly (yaw rate sensor) CAN communication system Driving support ECU assembly Wire harness or connector U0126 When the engine switch is on (IG), a communication error between the steering angle sensor and the driving support ECU assembly is detected for approximately 4 seconds. CAN communication system Steering angle sensor Driving support ECU assembly Wire harness or connector U0129 When the engine switch is on (IG), a communication error between the brake actuator assembly (skid control ECU) and the driving support ECU is detected for approximately 3 second. When the engine switch is on (IG), a communication error between the brake actuator assembly (skid control ECU) and the seat belt control ECU is detected for approximately 3 seconds. Brake actuator assembly (skid control ECU) CAN communication system Seat belt control ECU Driving support ECU assembly Wire harness or connector U0140 When the engine switch is on (IG), a communication error between the main body ECU and seat belt control ECU is detected for approximately 6 seconds. CAN communication system Main body ECU (multiplex network body ECU) Seat belt control ECU Wire harness or connector U0142 When the engine switch is on (IG), a communication error between the main body ECU and driving support ECU assembly is detected for approximately 14.2 seconds or more. CAN communication system Main body ECU (multiplex network body ECU) Driving support ECU assembly Wire harness or connector U0151 When the engine switch is on (IG), a communication error between the airbag sensor assembly and seat belt control ECU is detected for approximately 6 seconds. CAN communication system Airbag sensor assembly Seat belt control ECU Wire harness or connector U0235 When the engine switch is on (IG), a communication error between the millimeter wave radar sensor assembly and the driving support ECU assembly is detected for approximately 1 seconds. CAN communication system Millimeter wave radar sensor assembly Driving support ECU assembly Wire harness or connector U1002 When the engine switch is on (IG), a communication error between the millimeter wave radar sensor assembly and driving support ECU is detected for approximately 2 second. Millimeter wave radar sensor assembly CAN communication system Driving support ECU assembly Wire harness or connector U1100 When the engine switch is on (IG), a communication error between the seat belt control ECU and the driving support ECU assembly is detected for approximately 10 seconds. CAN communication system Driving support ECU assembly Seat belt control ECU Wire harness or connector U1104 When the engine switch is on (IG), a communication error between the driving support ECU assembly and the millimeter wave radar sensor assembly is detected for approximately 1 second. When the engine switch is on (IG), a communication error between the driving support ECU assembly and the network gateway ECU is detected for approximately 1 second. When the engine switch is on (IG), a communication error between the driving support ECU assembly and the seat belt control ECU is detected for approximately 1 second. CAN communication system Millimeter wave radar sensor assembly Driving support ECU assembly Seat belt control ECU Wire harness or connector Network gateway ECU

Scheme 194

The driving support ECU assembly receives a pre-collision system on/off signal from the pre-collision system cancel switch assembly.

Scheme 195

This circuit supplies power to the seat belt control ECU when the engine switch is on (IG).

Scheme 196

See also:
• COMPONENTS [06/2012 - ]
• COMPONENTS [06/2012 - ]
• REMOVAL [06/2012 - ]