Initialization [10/2023 - ]

WARNING: This page is about a different car, the 2024 Lexus LS 500h. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION
1. The zero point of the occupant classification sensors may deviate in the following situations. To ensure sensor accuracy, be sure to perform Zero Point Calibration.
  1. The airbag ECU assembly is replaced.
    HINT:
    
    As the zero point is not automatically stored in a new airbag ECU assembly, it is necessary to perform zero point calibration after replacing the airbag ECU assembly.
  2. Accessories (seatback tray, seat cover, etc.) are installed or removed.
    HINT:
    
    As the weight of accessories will be added or decreased to the weight of the occupant, the system will not be able to perform classification accurately.
  3. The front passenger seat is removed from the vehicle.
    HINT:
    
    As the seat frame will warp slightly when the bolts that are used to install the front passenger seat are tightened, the load applied to the occupant classification sensor will change and the system will not be able to perform classification accurately.
  4. Any of the bolts that are used to install the front passenger seat are removed and reinstalled.
    HINT:
    
    As the seat frame will warp slightly when the bolts that are used to install the front passenger seat are tightened, the load applied to the occupant classification sensor will change and the system will not be able to perform classification accurately.
  5. The passenger airbag ON/OFF indicator ("ON") illuminates when the front passenger seat is not occupied or the airbag OFF indicator illuminates when the front passenger seat is occupied (by an adult).
    HINT:
    
    If any load or pressure is applied to the occupant classification sensors, the system will not be able to perform classification accurately.
  6. An occupant classification sensor collision detection DTC is output due to an accident or a collision.
    HINT:
    
    If the seat frame or vehicle floor has become deformed and additional pressure is applied to the occupant classification sensor, the system will not be able to perform classification accurately.

ZERO POINT CALIBRATION

NOTE:

Make sure that the front passenger seat is not occupied before performing the operation.

Zero point calibration procedure

Check that all of the following conditions are met:
- The vehicle is parked on a level surface.
- No objects are placed on the front passenger seat.
- No objects are touching the front passenger seat.

Adjust the seat position according to the table below.

Adjustment Item	Position
Slide Direction	Rearmost position
Headrest Height	Lowest position
Recline Angle	Upright position

Perform zero point calibration by following the prompts on the GTS screen.

Body Electrical > SRS Airbag > Utility

Tester Display
Occupant Detection Sensor Zero Point Calibration

"Occupant Detection Sensor Zero Point Calibration is complete." is displayed.

Clear the Vehicle Control History (RoB).

Body Electrical > SRS Airbag > Utility

Tester Display
Vehicle Control History (RoB)

Check for Vehicle Control History (RoB).

Body Electrical > SRS Airbag > Utility

Tester Display
Vehicle Control History (RoB)

X20D0 is not output.

HINT:

Refer to the GTS operator's Service Information for further details.

If Occupant Detection Sensor Zero Point Calibration does not complete normally, check the Error Code List to determine the cause of malfunction.

ERROR CODE CHART

Error Code	Item Name	Cause	Countermeasure
01	Out of FI Load Sensor Upper Limit Standard	When any of the following conditions is detected: The sensor load value before learning is not as specified (upper limit exceeded) The sensor load value after learning is not as specified (upper limit exceeded)	Perform the following Check whether the vehicle and seat are subject to vibration or a load Check front seat assembly RH installation Refer to INSTALLATION [10/2023 - ] Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
02	Out of FI Load Sensor Lower Limit Standard	When any of the following conditions is detected: The sensor load value before learning is not as specified (below lower limit) The sensor load value after learning is not as specified (below lower limit)	Perform the following Check whether the vehicle and seat are subject to vibration or a load Check front seat assembly RH installation Refer to INSTALLATION [10/2023 - ] Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
03	Out of RI Load Sensor Upper Limit Standard	When any of the following conditions is detected: The sensor load value before learning is not as specified (upper limit exceeded) The sensor load value after learning is not as specified (upper limit exceeded)	Perform the following Check whether the vehicle and seat are subject to vibration or a load Check front seat assembly RH installation Refer to INSTALLATION [10/2023 - ] Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
04	Out of RI Load Sensor Lower Limit Standard	When any of the following conditions is detected: The sensor load value before learning is not as specified (below lower limit) The sensor load value after learning is not as specified (below lower limit)	Perform the following Check whether the vehicle and seat are subject to vibration or a load Check front seat assembly RH installation Refer to INSTALLATION [10/2023 - ] Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
10	Nonvolatile Memory Storage Failure	When a memory malfunction caused by either of the following is detected: Writing failure IGR low voltage (below 8 V)	Perform the following Check for DTCs Check vehicle control history (RoB) Refer to VEHICLE CONTROL HISTORY (RoB) [10/2023 - ] Measure IGR terminal voltage Refer to TERMINALS OF ECU [10/2023 - ] HINT: If below 8 V, check the power source circuit. Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the airbag ECU assembly. Refer to REMOVAL [10/2023 - ]
11	Zero Point Learning Timeout	Occupant Detection Sensor Zero Point Calibration does not complete within 2 seconds (within the specified number of seconds)	Perform the following Clear the vehicle control history (RoB) Refer to VEHICLE CONTROL HISTORY (RoB) [10/2023 - ] Check vehicle control history (RoB) Refer to VEHICLE CONTROL HISTORY (RoB) [10/2023 - ] Check whether the vehicle and seat are subject to vibration or a load Check front seat assembly RH installation Refer to INSTALLATION [10/2023 - ] Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the airbag ECU assembly. Refer to REMOVAL [10/2023 - ]
13	FI Load Sensor Malfunction	When a load sensor malfunction is detected	Perform the following Check for DTCs Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
14	RI Load Sensor Malfunction	When a load sensor malfunction is detected	Perform the following Check for DTCs Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]
17	FI LIN Communication Lost	When a communication malfunction with the load sensor is detected	Perform the following Check for DTCs Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, Refer to "LIN Communication Circuit" Refer to LIN Communication Circuit [10/2023 - ]
18	RI LIN Communication Lost	When a communication malfunction with the load sensor is detected	Perform the following Check for DTCs Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, Refer to "LIN Communication Circuit" Refer to LIN Communication Circuit [10/2023 - ]
21	ECU Malfunction	When an airbag ECU assembly malfunction is detected	Perform the following Check for DTCs Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the airbag ECU assembly. Refer to REMOVAL [10/2023 - ]
22	IGR Low Voltage	When IGR voltage (below 8 V or 16 V or higher) is detected	Perform the following Check vehicle control history (RoB) Refer to VEHICLE CONTROL HISTORY (RoB) [10/2023 - ] Measure IGR terminal voltage Refer to TERMINALS OF ECU [10/2023 - ] HINT: When IGR low voltage (8 V or 16 V or higher) is detected
23	Load Unstable	When any of the following conditions is detected: The vehicle and seat are subject to vibration or a load Sensor malfunction	Perform the following Check whether the vehicle and seat are subject to vibration or a load Perform Occupant Detection Sensor Zero Point Calibration again HINT: If the error code is output again, replace the front seat adjuster assembly RH (occupant classification sensor). Refer to DISASSEMBLY [10/2023 - ]