Vehicle: 2013 CX-5 with 6-speed stick shift.

I had a dead battery, and when I recharged it (and removed and cleaned the terminal clamps) this strange speedometer behavior started. If the car is shut off, the needle points straight up; if the engine is running and the car is still, it reads 30. As I accelerate, comparing to speedometer reading on my phone it is consistently 30 MPH high, at all speeds. To be clear, this is NOT a matter of showing KPH instead of MPH; it's just 30 MPH high, always.

I assume it's either the speedo in the cluster (which appears to mean replacing the cluster), or a bad vehicle speed sensor, or else something is shorted.

My questions:
1. Has anyone seen this? What did you learn about what was causing it? I'm about to just buy the speed sensor (if I can find it - see question 2), and hope, then replace the instrument cluster if that doesn't work. But I'd rather make an informed repair.
2. The odometer registers correctly, which makes me think the vehicle speed sensor is probably okay; anyone have enough knowledge to know if that's correct?
3. Does anyone know where the speed sensor is on a CX5 with stick shift? Google informs me that there are speed sensors on the front wheels for ABS, but I'm guessing those don't feed the speedometer. Anyone know?

Thanks for any assistance anyone is able to offer.

 

You need to have your battery load tested. It reads of a bad or failing battery.
You will need to completely check the battery connection both at the battery, the ground at the frame or chassis and positive cable at the stater.

Hopefully you removed and replaced the battery terminal cables in the proper procedure.

please don’t post that you know the battery is ok or the date you bought it . Unless u did above ^^^^^^^


Then you need to scan the ECU for not only active DTC but pending or permanent files. Might as well also while you are there check the I/ M monitors . This is where you will get a clue to a few things.

There may be slim chance you might need a ECU flash or pass-through with the latest available ECU update. That you will not be able to do. Dealer or an independent service shop that has the Flashing tool and programs.

google is not your friend unless you actually did some form of schooling or training on diagnostic auto service.

9 out of 10 customers that use google that bring their vehicles in the shop are wrong about what is wrong.

 

Thanks for your reply. Not a new battery, but it has been working fine. I had removed it to jump start another car, and cleaned it up before putting it back in the Mazda. I'll take my VOM out and test voltage output to be sure, thought.

As for "removed and replaced the battery terminals in the proper procedure", I'm not quite sure what you mean by that. I'm an "old-school" shade tree mechanic, in that I understand the mechanical bits better than some of the electrical tech; I've never been aware of any "proper procedure" apart from loosening the bolts and pulling the cables off, then putting the cables back on the battery and tightening the bolts. Could you explain what additional procedure I need to follow?

Thanks!

 

I'm still curious what the correct procedure might be; but just the words prompted me to go pull the negative cable and then reattach, and the problem is solved!

Thanks, I don't think I would have bothered to do that without your message.

-joe

 

Joe, I can only guess based on this response ^^^ why your problem was corrected.

But 2 things I would not ignore no matter what you think?

get your battery load tested you may be very surprised about the results. Or ignore my recommendation and keep your AAA card handy!

And read a HOW-TO remove and replace a battery.

Lastly you Mazda and it is charging is controlled by the ECU . You have several vital and very expensive on-board computers (ECU,TCM,BCM,SRS etc.) all rely on a healthy battery and anything less can affect their operation or cause them to fail needing to be replaced. $$$system as well its ECU ,TCM
I would highly recommend NOT to use your Mazda to jump other vehicles or to remove the battery to jump another vehicle.
Invest in a battery jumper box. They are cheap see Amazon.

ASE

 

I agree with buying a battery jump box. I too am an old school amateur mechanic and have been so for nearly 50 years.......back in the day it was no problem to use another vehicle to jump a dead battery in a vehicle as there were not a lot of electronics in those cars. In today's cars, it's a completely different game. I have several jump boxes now, and I haven't picked up my very nice jumper cables in several years now. I usually take a completely charged jump box with me when I go on a trip these days......you just never know, and it is comforting to know it's there if you or someone else needs it!

 

MeB2000