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 P1784:00 (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.
1		No	Go to the next step.
2	INSPECT ATF LEVEL Inspect the ATF level. (See AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION [EV6A-EL, EV6AX-EL (US)] .) Is there any malfunction?	Yes	Adjust the ATF level to the specification, then go to the next step. (See AUTOMATIC TRANSAXLE FLUID (ATF) ADJUSTMENT [EV6A-EL, EV6AX-EL (US)] .)
2		No	Replace the automatic transaxle. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6A-EL (US)] .) (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6AX-EL (US)] .)
3	PERFORM STALL TEST TO VERIFY DTCs Clear the DTC using the M-MDS. (See CLEARING DTC .) Perform the stall test in the reverse (R) position. (See MECHANICAL SYSTEM TEST [EV6A-EL, EV6AX-EL (US)] .) Perform the DTC inspection using the M-MDS. (See DTC INSPECTION .) Are any DTCs present?	Yes	Replace the automatic transaxle. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6A-EL (US)] .) (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6AX-EL (US)] .)
3		No	Go to the next step.
Repair completion verification	PERFORM ON-BOARD DIAGNOSTIC TEST Perform the on-board diagnostic test. (See ON-BOARD DIAGNOSTIC TEST MODE (TCM) .) Are any DTCs present?	Yes	Replace the automatic transaxle. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6A-EL (US)] .) (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6AX-EL (US)] .)
Repair completion verification		No	Drive the vehicle for 10 min or more. DTCs are displayed: Replace the automatic transaxle. (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6A-EL (US)] .) (See AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION [EV6AX-EL (US)] .) No DTCs are displayed: DTC troubleshooting completed.