2019 Signature - AT Transmission Malfunction

:
2010 CX-9 GT, 2017 Mazda6 GT
Wife was driving our 2019 Signature with 14K miles and the AT Transmission Malfunction message came on. She drove home. I started car, and check engine light was on. Went on a 3 mile drive around the block (seemed to shift normally) and check engine light remained on. Dealer recommended towing in.

I didn't bother pulling the code, but it's under warranty, no point.

Any insight into this error message?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Wife was driving our 2019 Signature with 14K miles and the AT Transmission Malfunction message came on. She drove home. I started car, and check engine light was on. Went on a 3 mile drive around the block (seemed to shift normally) and check engine light remained on. Dealer recommended towing in.

I didn't bother pulling the code, but it's under warranty, no point.

Any insight into this error message?
Yes, if we don’t know the error code, there’s not much we can say about “AT Transmission Malfunction” message. Do tell us what the dealer found about the message.
 
:
2010 CX-9 GT, 2017 Mazda6 GT
Fault code P0847 transmission fluid pressure “B” circuit

Per TSB 05-004 19 replace A and B Oil Pressure switches (FZ01-21-2C0 and FZ01-21-2J0)
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
:
Plano, Texas, USA
Fault code P0847 transmission fluid pressure “B” circuit

Per TSB 05-004 19 replace A and B Oil Pressure switches (FZ01-21-2C0 and FZ01-21-2J0)
Thanks for the update. Here’s the description of TSB 05-004/19:

DESCRIPTION

Some vehicles may experience the check engine light and automatic transaxle warning light ON with one or more of these DTCs stored in the TCM memory (P0842, P0847, P0872, P0877, P0780, P1738).

• P0842:00 - Oil pressure switch No. 1 (oil pressure switch B) stuck on
• P0847:00 - Oil pressure switch No. 2 (oil pressure switch A) stuck on
• P0872:00 - Oil pressure switch No. 3 (oil pressure switch A) stuck on
• P0877:00 - Oil pressure switch No. 4 (oil pressure switch B) stuck
• P0780:00 - Gear shifting malfunction
• P1738:00 Automatic transaxle internal malfunction

This is caused by the oil pressure switch A and/or B at the control valve body temporarily or permanently getting stuck due to contamination entering the passage. To correct the problem, some mass production changes have been implemented to reduce contamination and improve the DTC diagnostic logic.
 
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