Lexus IS250 · Service Manual STEERING

B2621

Diagnostic trouble codes

DESCRIPTION

The multiplex tilt & telescopic ECU forms a network with the ECUs of other systems through the communication bus. Each ECU informs the other ECUs that it is connected to the network by outputting a specified signal (periodical signal) onto the communication bus on a regular schedule. The multiplex tilt & telescopic ECU detects the connection of each ECU based on the signal.
DTC No.
 Detection Item
 Trouble Area
B2621
 Periodical signal from the specified ECU has stopped.
  1. Multiplex communication system
  2. Main body ECU RH (Cowl side J/B RH)
  3. Front power seat switch (Position control ECU) (Driver Side)
  4. Windshield wiper switch assembly (Combination switch ECU)
  5. Power source control ECU
  6. Multiplex tilt & telescopic ECU

INSPECTION PROCEDURE


1. CHECK ANY OTHER DTCS OUTPUT (MULTIPLEX COMMUNICATION SYSTEM)

  1. Check if multiplex communication system DTC B1200, B1210, B1272 or B1278 is output.

    Result:
    DTC Condition
    		 Proceed to
    No output
    		 A
    B1200 is output
    		 B
    B1210 is output
    		 C
    B1272 is output
    		 D
    B1278 is output
    		 E

    HINT:
    1. If any other codes besides B2621 are output, perform troubleshooting for those DTCs first.
    2. DTC B1200 indicates a body ECU communication stop malfunction in the multiplex communication system.
    3. DTC B1210 indicates a power source control ECU communication stop malfunction in the multiplex communication system.
    4. DTC B1272 indicates a power seat ECU communication stop malfunction in the multiplex communication system.
    5. DTC B1278 indicates a combination switch ECU communication stop malfunction in the multiplex communication system.



 B
Go to step 2

C
Go to step 3

D
Go to step 4

E
Go to step 5
A

END

2. READ VALUE OF INTELLIGENT TESTER (MAIN BODY ECU RH (COWL SIDE J/B RH) COMMUNICATION SIGNAL)

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester on.

  1. Select "Receive from Body" from DATA LIST.

  1. Check the signal communication state of the main body ECU RH (cowl side J/B RH) on the tester screen.

    TILT & TELESCO: 
    Item
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Receive from Body
    		 Communication state of body ECU signal / OK or Interruption
    		 OK: Communication is normal
    Interruption: Communication is interrupted

    OK:
    "OK" is displayed.



 NG
REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)
OK

REPLACE MULTIPLEX TILT & TELESCOPIC ECU

3. READ VALUE OF INTELLIGENT TESTER (DRIVER SEAT ECU COMMUNICATION SIGNAL)

  1. Select "Receive from Seat ECU" from DATA LIST.

  1. Check the signal communication state of the front power seat switch (position control ECU (Driver Side)) on the tester screen.

    TILT & TELESCO: 
    Item
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Receive from Seat ECU
    		 Communication state of seat ECU signal / OK or Interruption
    		 OK: Communication is normal
    Interruption: Communication is interrupted

    OK:
    "OK" is displayed.



 NG
REPLACE FRONT POWER SEAT SWITCH (POSITION CONTROL ECU (DRIVER SIDE))
OK

REPLACE MULTIPLEX TILT & TELESCOPIC ECU

4. READ VALUE OF INTELLIGENT TESTER (COMBINATION SWITCH ECU COMMUNICATION SIGNAL)

  1. Select "Receive from Combi" from DATA LIST.

  1. Check the signal communication state of the combination switch ECU on the tester screen.

    TILT & TELESCO: 
    Item
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Receive from Combi
    		 Communication state of combination switch ECU signal / OK or Interruption
    		 OK: Communication is normal
    Interruption: Communication is interrupted

    OK:
    "OK" is displayed.



 NG
REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY (COMBINATION SWITCH ECU)
OK

REPLACE MULTIPLEX TILT & TELESCOPIC ECU

5. READ VALUE OF INTELLIGENT TESTER (POWER SOURCE CONTROL ECU COMMUNICATION SIGNAL)

  1. Select "Power ECU Info" from DATA LIST.

  1. Check the signal communication state of the power source control ECU on the tester screen.

    TILT & TELESCO: 
    Item
    		 Measurement Item / Range (Display)
    		 Normal Condition
    Power ECU Info
    		 Communication state of power source control ECU signal / OK or Interruption
    		 OK: Communication is normal
    Interruption: Communication is interrupted

    OK:
    "OK" is displayed.



 NG
REPLACE POWER SOURCE CONTROL ECU
OK

REPLACE MULTIPLEX TILT & TELESCOPIC ECU


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