LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2021 >> CX-30 Turbo Premium >> Repair and Diagnosis >> External Pages >> Different car >> Section 19 (On-Board Diagnostics - Automatic Transaxle System (EV6A-El, EV6AX-El)) >> DTC U0074-00: Can System Communication Error (Local Can Between TCM And Pcm) (TCM) (Us) >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.
DTC U0074:00 (TCM, EV6A-EL, EV6AX-EL, US) DIAGNOSTIC PROCEDURE

Step Inspection Results Action
1 VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY
  • Verify related Service Bulletins, on-line repair information, or Service Information availability.
  • Is any related information available?
Yes Perform repair or diagnosis according to the available information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
2 VERIFY PCM DTC
  • Perform the PCM DTC inspection using the M-MDS. (See DTC INSPECTION .)
  • Are any DTCs present?
Yes DTC U0074:00 is displayed:
  • CAN communication line can be considered the cause.
  • Refer to the wiring diagram and verify whether or not there is a common connector between TCM and PCM.

If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a malfunction.
    • Repair or replace the malfunctioning part.

If there is no common connector:
  • Repair or replace the wiring harness.
  • Go to the next step.

DTC other than U0074:00 is displayed:
No Go to the next step.
Repair completion verification 1 VERIFY DTC TROUBLESHOOTING COMPLETED
  • Clear the DTC using the M-MDS. (See CLEARING DTC .)
  • Perform the following procedure to ensure that the DTC has been resolved:
    • Switch the ignition ON (engine off or on).
  • Perform the DTC inspection using the M-MDS. (See DTC INSPECTION .)
  • Is the same Pending DTC present?
Yes Replace the control valve body, then go to the next step.
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [EV6A-EL, EV6AX-EL (US)] .)
No Go to the next step.
Repair completion verification 2 VERIFY IF OTHER DTCs DISPLAYED
  • Perform the DTC inspection. (See DTC INSPECTION .)
  • Are any other DTCs displayed?
Yes Repair the malfunctioning location according to the applicable DTC troubleshooting.
(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE (TCM) (US) .)
No DTC troubleshooting completed.