Code No. B1731 ENG ECU authentification timeout


caution
  • When the diagnosis code No. B1731 is set, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.

DIAGNOSTIC FUNCTION



JUDGEMENT CRITERIA


Check Conditions
  • At engine starting certification
Judgment Criterion
  • At the engine starting certification with engine-ECU, necessary data cannot be received from engine-ECU via CAN bus line.

PROBABLE CAUSES



  • Malfunction of the CAN bus line
  • Malfunction of engine-ECU
  • Malfunction of OSS-ECU

DIAGNOSIS PROCEDURE


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