Obd2 not working after battery replacement

[speedbird1]

My small bit to add to this thread is, set aside an hour to yourself, and check each and every individual fuse, one at a time, literally remove fuse, check, replace and repeat. Yes I know it's laborious but at least you get a definitive conclusion.

 

[Mitchbakr]

Hi all! My CX-5's Obd2 port is not responsive after recent battery change. I believe I must have blown then Obd2 fuse. Does anyone know what fuse or fuse number it is?

I have the same issue. AutoZone replace my battery connected their battery saver or setting saver and did not work. Check engine light came on has stayed on consistently ever since I’ve tried three different OBD two readers with same results no power to the reader. Do I need to take it to a dealer? 2016 Mazda CX-5

 

[blautens]

Similar problem - not seen any definite search results with solutions for people with this issue - I replaced the battery on our 2018 CX-5 and used a Schumacher SEC-12V battery saver that plugs into the OBD2 port as I was afraid of losing a myriad of settings in the CMU, lights, windows, etc. - then later after the swap my wife noticed the CEL was on and I went to plug in both of my OBD2 scanners and neither powered up. I also noticed the auto up power windows weren't working, so the memory saver didn't work. All this leads me to believe a fuse might be blown, perhaps by my memory saver. At least I hope that's all it is. I've printed out the fuse diagram and I'm looking forward to a an hour of probing (once I confirm no power on the OBD2 port itself using a multimeter). I'll post with results, good or bad or null. This much I can tell you, it's not F54 Room fuse under the hood - nor I believe any of the underhood fuses - they all tested ok with a test light.

FWIW, I went through every fuse with a test light, under dash and under hood, and even pulled possibly related fuses and tested with a multimeter and did not find any issues with the fuses. No solution so far, and since my local Mazda dealer is really, really bad about service (recommending bizarre amounts of service and replacement parts for our other Mazdas in a clear scam when my daughter took her car in instead of me), I'm still hunting for answers.

 

[blautens]

FWIW, I went through every fuse with a test light, under dash and under hood, and even pulled possibly related fuses and tested with a multimeter and did not find any issues with the fuses. No solution so far, and since my local Mazda dealer is really, really bad about service (recommending bizarre amounts of service and replacement parts for our other Mazdas in a clear scam when my daughter took her car in instead of me), I'm still hunting for answers.

For those with this issue, thanks to this post - it's the F37 7.5A ENG +B fuse that was blown (under hood fuse box). Thanks so much - hope this helps others!

 

[Mitchbakr]

For those with this issue, thanks to this post - it's the F37 7.5A ENG +B fuse that was blown (under hood fuse box). Thanks so much - hope this helps others!

Resolved my issue. obd now works and cleared the check engine light. I thought for certain I had looked at that particular fuse but it was definitely blown. Thanks so much.