Pre-Collision System [Diagnostic Codes & Circuit Tests]: Overview Toyota Sienna III

DESCRIPTION

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

Scheme 92

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

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

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

Scheme 93

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

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

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 94

This DTC is stored when a malfunction in the vehicle stability control system is detected. This circuit consists of the skid control ECU and seat belt control ECU. Signals are sent from the skid control ECU using the CAN communication.

The seat belt control ECU is connected to the main body ECU using CAN communication.

The seat belt control ECU receives vehicle model information from the main body ECU and determines whether the seat belt buckle switch information from the center airbag sensor assembly is for the driver seat or the passenger seat.

DTC B2064 is stored when the CAN communication frame with the main 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 side buckle switch circuit or passenger side buckle switch circuit.

*1: w/ Smart Key System

*2: w/o Smart Key System

Scheme 95

Scheme 96

This DTC is stored when CAN communication between the driving support ECU and skid control ECU is interrupted.

This circuit consists of the driving support ECU, 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 and skid control ECU.

The seat belt control ECU receives collision information from the driving support ECU and skid control ECU via CAN communication, and tightens the seat belt by operating the motor inside the front seat outer belt.

When the driving support ECU detects a malfunction in the dynamic radar cruise control system and pre-collision 2 system, the malfunction information is sent to the seat belt control ECU, which outputs this DTC.

When DTC B2090 is detected, other DTCs are also stored by the driving support ECU (dynamic radar cruise control system and pre-collision 2 system).

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The skid control ECU receives vehicle stability signals from the yaw rate sensor and sends the signals to the driving support ECU and ECM. If the skid control ECU detects that the yaw rate sensor is malfunctioning, the skid control ECU sends a malfunction signal to the driving support ECU, and the driving support ECU stores DTC C1A46.

The skid control ECU receives steering rotation angle information from the steering angle sensor, and sends the information to the driving support ECU through the CAN communication line.

If the skid control ECU detects a malfunction of the steering angle sensor, it sends a malfunction signal to the driving support ECU and records a DTC.

Based on pre-collision control, the driving support ECU communicates to the driver to be careful. The driving support ECU performs this by sending a sounding signal to the skid control ECU to sound the skid control buzzer.

When the skid control ECU detects a malfunction in the VSC warning buzzer circuit, a malfunction signal is sent to the driving support ECU, and a DTC is stored. Although the skid control ECU sends a malfunction signal to the driving support ECU, the vehicle stability control system does not stored a relevant malfunction detection DTC.

The stop light switch assembly outputs a brake pedal operation signal to the driving support ECU. Based on the signal, the driving support ECU cancels cruise control.

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

1. The driving support ECU sends vehicle speed and vehicle condition information to the millimeter wave radar sensor. The millimeter wave radar sensor then sends information on the presence, distance, and relative speed of objects ahead to the driving support ECU. The driving support ECU sends this information to the ECM and performs pre-collision system (DTC U1104). DTC No. DTC Detection Condition Trouble Area U0122 When the ignition switch is ON, a communication error between the skid control ECU and the driving support ECU is detected for approx. 1 second. When the ignition switch is ON, a communication error between the skid control ECU assembly and the seat belt control ECU is detected for approx. 1 second. Brake actuator (skid control ECU) CAN communication system Seat belt control ECU Driving support ECU U0123 When the ignition switch is ON, a communication error between the yaw rate sensor and the driving support ECU is detected for approx. 1 second. Yaw rate sensor CAN communication system Driving support ECU U0126 When the ignition switch is ON, a communication error between the steering sensor and the driving support ECU is detected for approx. 1 second. Steering angle sensor CAN communication system Driving support ECU U0140 While ignition switch is ON, communication stop between main body ECU and seat belt control ECU continues for 1 second or more. Main body ECU CAN communication system Seat belt control ECU U0151 While ignition switch is ON, communication stop between center airbag sensor and seat belt control ECU continues for 1 second or more. Center airbag sensor assembly CAN communication system Seat belt control ECU U0235 When the ignition switch is ON, a communication error between the millimeter wave radar sensor and the driving support ECU is detected for approx. 1 second. Communication circuit Millimeter wave radar sensor Driving support ECU U1100 When the ignition switch is ON, a communication error between the seat belt control ECU and the driving support ECU is detected for approx. 1 second. Seat belt control ECU CAN communication system Driving support ECU U1104 When the ignition switch is ON, a communication error between the driving support ECU and the millimeter wave radar sensor is detected for approx. 1 second. Communication circuit Millimeter wave radar sensor Driving support ECU CAN communication system

Scheme 97

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

Scheme 98

Scheme 99

Scheme 100

1. READ VALUE USING TECHSTREAM (PRE-COLLISION BRAKE CANCEL SWITCH) Use the Data List to check if the pre-collision brake cancel switch is functioning properly. PRE-COLLISION 2 Tester Display Measurement Item/Range Normal Condition Diagnostic Note Pre-Collision Brake OFF Switch Pre-collision system cancel switch status/ON or OFF ON: Pre-collision brake cancel switch on OFF: Pre-collision brake cancel switch off - OK On screen, each item changes between ON and OFF according to above chart. NG --> See step 2 OK --> See step 5
2. INSPECT PRE-COLLISION BRAKE CANCEL SWITCH Remove the pre-collision brake cancel switch. Refer to «REMOVAL»(ref-494247-S07247866322012081000000). Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition 1 - 2 Pressed Below 1 ohms Not pressed 10 kohms or higher TEXT IN ILLUSTRATION *1 Component without harness connected (Pre-collision Brake Cancel Switch) Reinstall the pre-collision brake cancel switch. Refer to «INSTALLATION»(ref-494247-S01362510582012081000000). NG --> See step 6 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (PRE-COLLISION BRAKE CANCEL SWITCH - DRIVING SUPPORT ECU) Disconnect the D4 pre-collision brake cancel switch connector. Disconnect the A44 driving support ECU connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition D4-1 - A44-5 (PBSW) Always Below 1 ohms D4-1 - Body ground Always 10 kohms or higher Reconnect the driving support ECU connector. Reconnect the pre-collision brake cancel switch connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (PRE-COLLISION BRAKE CANCEL SWITCH - BODY GROUND) Disconnect the D4 pre-collision brake cancel switch connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition D4-2 - Body ground Always Below 1 ohms TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Pre-collision Brake Cancel Switch) Reconnect the pre-collision brake cancel switch connector. NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-494264-S17975973692012081000000)
6. REPLACE PRE-COLLISION BRAKE CANCEL SWITCH. Refer to «REMOVAL»(ref-494247-S07247866322012081000000)
7. REPLACE DRIVING SUPPORT ECU. Refer to «REMOVAL»(ref-494177-S37701999352012081000000)

This circuit supplies power to the seat belt control ECU.

Scheme 101

See also:
• REMOVAL
• REMOVAL