LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2015 >> 3 SV, Automatic Trans >> Repair and Diagnosis (Single Page) >> Transmission >> Automatic Trans >> Automatic Transaxle On-Board Diagnostic >> DTC U0074: 00 Can System Communication Error (Local Can Between TCM And Pcm) >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC U0074: 00 Can System Communication Error (Local Can Between TCM And Pcm): Notes

DTC U0074:00 (FW6A-EL) - DIAGNOSTIC PROCEDURE

DTC U0074:00  CAN system communication error (local CAN between TCM and PCM) 
DETECTION CONDITION 
  • Under the following condition, a communication error (local CAN between TCM and PCM) occurs:
    • Battery voltage is 10 V or more. 

Diagnostic support note 
  • The check engine light does not illuminate.
  • The automatic transaxle warning light does not illuminate.
  • PENDING CODE is available.
  • FREEZE FRAME DATA is not available.
  • DTC is stored in the TCM memory.
FAIL-SAFE FUNCTION 
  • Set to TCC control.
  • Inhibits learning control.
  • Inhibits manual mode.
  • Inhibits neutral idle control.
  • Inhibits AAS.
  • Inhibits 5GR and 6GR.
  • Inhibits shift down when the accelerator pedal is depressed.
POSSIBLE CAUSE 
  • CAN communication line malfunction between TCM and PCM (local CAN between TCM and PCM)
  • PCM DTC is stored.
  • TCM malfunction
SYSTEM WIRING DIAGRAM  Not applicable