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DTC B2304: Communication Error from Backup Relay (BURDIAG2) to Sub Battery Module [12/2017 - 10/2023]: Description

The sub-battery module assembly receives RD12 signals from the backup relay.

RD12 signals are PWM communication (Pulse Width Modulation: Modulates pulse width according to duty ratio) and indicates the normal/malfunction condition of the backup relay.

GTY820097Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate Memory
B2304 Communication Error from Backup Relay (BURDIAG2) to Sub Battery Module This DTC is stored when a malfunction is detected in communication from the backup relay (RD12) to the sub-battery module assembly continuously for 10 seconds.
(3 trip detection logic)
  • Harness or connector
  • Backup relay
  • Sub-battery module assembly
Comes on DTC stored

HINT: 

The details of a DTC can be checked by using the DTC Sub Code of the freeze frame data that was recorded when the DTC was output.

DTC Sub Code Detail
"3E" Open or short to +B in backup relay signal line (RD12)
"3F" Short to ground in backup relay signal line (RD12)
"40" Waveform malfunction in backup relay signal line (RD12)