DTC B2321: Driver Side Door ECU Communication Stop: Procedure

1. Disconnect the 3B instrument panel junction block assembly connector.
2. Disconnect the K9 power window regulator motor (for driver side) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3B-30 (LIN2) - K9-9 (LIN)	Always	Below 1 Ω
   3B-30 (LIN2) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the instrument panel junction block assembly. Refer to REMOVAL .
   Fig 1: Inspecting Instrument Panel Junction Block Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   HINT: 

   This inspection is to check the LIN line in the instrument panel junction block assembly that connects the wire harness to the built-in main body ECU (multiplex network body ECU).

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3B-30 (LIN2) - MB-16 (LIN2)	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   *b

   Component without harness connected (Instrument Panel Junction Block Assembly)

NG → See step   6 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 2: Checking K9 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   K9-2 (B) - Body ground	Always	11 to 14 V

2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   K9-1 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Replace the power window regulator motor assembly (for driver side). Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTC. Refer to DTC CHECK / CLEAR .
2. Check for DTCs.

   OK

   DTC B2321 is not output.

NG → See step   7 

OK → END (POWER WINDOW REGULATOR MOTOR ASSEMBLY WAS DEFECTIVE)