Hi all, I have narrowed down a slow drain (4+ days sitting to dead battery..., about 900 miliamps when off) to the 15A Auto Transmission fuse. Anyone have the magic answer on where to go from here to end this drain? Thank you! (Note: When I pull the fuse, then re-insert, there is no draw until the next shut-down..., but don't want a life of repeating this process after EVERY DRIVE :-)

 

Assuming that 'Auto Transmission fuse' means the one that's labeled AT in the box, you can try removing and reattaching the connector that's located on top of the transmission case, and check to see if the drain has disappeared or if it's still present.

 

Thank you. You got me searching for access info, and I saw a short YouTube video on:

"2015 Mazda CX-5 Transfer Case Control Module location and removal"

It shows it sited at the driver's side kick plate at drivers door. Is this a possible other point?

Can you easily advise best access process for the top of the transmission? Is it from under the hood? Or do I need to tear the shifter out and go in thru the cabin?
Thank you so much!

 

First off, I need to mention that I have a 2020 CX-5, so things may not match up exactly, although I don't think Mazda changed the transmission configuration very much.

On my vehicle, I would have to remove the air box, in order to comfortably access the transmission connector that I'm referring to. I haven't had the need to do this on mine, but I can feel it down under the air box, so that would be what I would do to get to it. You might want to feel around gently with your hand and/or an inspection camera to confirm where it is on your vehicle, and that you also need to remove the air box. It's always possible that on your earlier model, you might have enough room to undo it without removing anything else, so take a close look first.

Although I'm not certain, I don't believe the transfer case module would play a part in your drain issue. The connector that I'm suggesting you recycle powers the TCM from that AT fuse, and also connects the TCM to the ECM and FBCM. So if the drain still is present after recycling that connector, the problem should be upstream of that connector (i.e. wiring/connectors, relays downstream of the AT fuse, including the fuse box circuitry). But if the drain goes away when you recycle the transmission connector, then the problem is either inside the transmission case (TCM/wiring) or with one of the other computers. In either case a complete transmission schematic of your vehicle (and possibly others as well) will be needed in order to diagnose further.