DTC B2621: Communication Interruption: Procedure

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

   Result

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

   HINT: 

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

B → See step   2 

C → See step   3 

D → See step   4 

E → See step   5 

A → See step   10 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Check the signal communication state of the main body ECU RH (cowl side junction block RH). Enter the following menus: Chassis / Tilt&Telescopic / Data List.
   TILT&TELESCOPIC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Receive from Body	Communication state of body ECU signal/ OK or Interpt	OK: Communication normal Interpt: Communication interrupted	-

   OK

   "OK" is displayed.

NG → REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH) 

OK → See step   8 

1. Check the signal communication state of the front power seat switch LH (position control ECU) on the Techstream. Enter the following menus: Chassis / Tilt&Telescopic / Data List.
   TILT&TELESCOPIC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Receive from Seat ECU	Communication state of seat ECU signal/ OK or Interpt	OK: Communication normal Interpt: Communication interrupted	-

   OK

   "OK" is displayed.

NG → See step   6 

OK → See step   8 

1. Check the signal communication state of the combination switch ECU on the Techstream. Enter the following menus: Chassis / Tilt&Telescopic / Data List.
   TILT&TELESCOPIC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Receive from Combi	Communication state of combination switch ECU signal/ OK or Interpt	OK: Communication normal Interpt: Communication interrupted	-

   OK

   "OK" is displayed.

NG → See step   7 

OK → See step   8 

1. Check the signal communication state of the power source control ECU on the Techstream. Enter the following menus: Chassis / Tilt&Telescopic / Data List.
   TILT&TELESCOPIC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Power ECU Info	Communication state of power source control ECU signal/ OK or Interpt	OK: Communication normal Interpt: Communication interrupted	-

   OK

   "OK" is displayed.

NG → See step   9 

OK → See step   8