DTC B2321: Driver Side Door ECU Communication Stop: Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch ON and turn the tester on.
3. Clear the DTCs.
4. Recheck the DTCs.
   RESULT
   
   

   Display (DTC Output)	Proceed to
   B2321	A
   No DTC output	B

B → SYSTEM IS OK 

A: Go to next step 

1. Connect Techstream to the DLC3.
2. Turn the ignition switch ON and turn the tester on.
3. Read the indication displayed on the tester.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Communication D-Door Motor	Connection status between power window regulator motor assembly (driver door) and main body ECU / OK or Stop	OK: Connection Stop: No connection	-

   OK

   OK is displayed on Techstream screen.

OK → REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU) 

NG: Go to next step 

1. Disconnect the H4 motor connector.
   Fig 1: Identifying Main Body ECU And Regulator Motor Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the E15 junction block connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   Tester Connection	Specified Condition
   H4-9 (LIN) - E15-23 (LIN2)	Below 1 Ω
   H4-9 (LIN) or E15-23 (LIN2) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK: Go to next step 

1. Connect Techstream to the DLC3.
2. Turn the ignition switch ON and turn the tester on.
3. Clear the DTCs.
4. Check whether DTC B2321 recurs 10 seconds or more after the ignition switch is turned ON.

   OK

   No DTC is output.

NG → REPLACE POWER WINDOW REGULATOR MOTOR ASSEMBLY (for Driver Side) 

OK → REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)