DTC B1321-87: Lost Communication with EMV Missing Message [09/2022 - ]: Procedure

1. Check each system for DTCs.

   Body Electrical > Combination Meter > Trouble Codes 

   Body Electrical > Navigation System > Trouble Codes 

2. Confirm the DTC combinations of the following table.

   DTC Output Pattern	DTC Output Part Name (Display on GTS)
   	Combination Meter Assembly (Combination Meter)	Radio and Display Receiver Assembly (Navigation System)
   1	B1321-87	U11D0-87
   2	B1321-87	Not output

   Result

   Result	Proceed to
   DTC output pattern 1	A
   DTC output pattern 2	B

Result: 

B 

See step  3

Result: 

A 

See step  2

1. Remove 1 of the following ECUs.
   • Radio and display receiver assembly

     HINT: 

     Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]

   • Combination meter assembly

     HINT: 

     Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]

2. Measure the resistance of the removed ECU.
   NOTE:

   • Refer to the following table for the specified conditions of each ECU.
   • If the specified conditions are met, repeat the inspection procedure from step (a) for another ECU.

   HINT: 

   If the results of an ECU are not as specified, it is suspected that the ECU is the cause of the DTC.

   1. Inspect the radio and display receiver assembly.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a	Component without harness connected (Radio and Display Receiver Assembly)

      Standard Resistance

      Tester Connection	Condition	Specified Condition
      I175-11 (CNH1) - I175-12 (CNL1)	Always	108 to 132 Ω

   2. Inspect the combination meter assembly.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      *a	Component without harness connected (Combination Meter Assembly)

      Standard Resistance

      Tester Connection	Condition	Specified Condition
      I5-32 (TX+) - I5-15 (TX-)	Always	108 to 132 Ω

      Result

      Result	Proceed to
      The results of all ECUs are as specified	A
      The results of the radio and display receiver assembly is not as specified	B
      The results of the combination meter assembly is not as specified	C

Result: 

A 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

B 

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 

Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]

Result: 

C 

REPLACE COMBINATION METER ASSEMBLY 

Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]

1. Clear the DTCs.

   Body Electrical > Combination Meter > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Disconnect the cable from the negative (-) auxiliary battery terminal.

   HINT: 

   By disconnecting the cable from the negative (-) auxiliary battery terminal, the internally stored information related to local bus communication for the combination meter assembly is reset.

2. Disconnect the I175 radio and display receiver assembly connector.
3. Connect the cable to the negative (-) auxiliary battery terminal.
4. Turn the ignition switch to ON.
5. Wait 30 seconds or more.
6. Check for DTCs.

   Body Electrical > Combination Meter > Trouble Codes 

   HINT: 

   By resetting the internally stored information related to local bus communication, the detection conditions of DTC B1321-87 are not met as the combination meter assembly does not detect the radio and display receiver assembly. If the combination meter assembly is operating normally, DTC B1321-87 will not be stored.

   Result

   Result	Proceed to
   DTC B1321-87 is not output	A
   DTC B1321-87 is output	B

Result: 

A 

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY 

Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]

Result: 

B 

REPLACE COMBINATION METER ASSEMBLY 

Refer to REMOVAL [09/2022 - 11/2022] , or refer to REMOVAL [11/2022 - 09/2024] , or refer to REMOVAL [09/2024 - ]