ND Start problem - key ?

Get in car Sat am , (a 2015 sport nav) ,   belt on, door closed, depress clutch  and push start button. Nowt . Hm- check door is closed - not sure it makes any difference but at 6am it was all I could  think of. Car starts. 80 miles later,  stop and restart as normal , but 60 miles later fill up, press button , nowt again. Swear , try again , starts. Another 6 starts since - all ok .

     Ideas please ? Is key battery most likely cause? (I assume they have batteries- never had to replace one?)   

 

PS - And now, Monday am ,  I am locked out of the car. Tried spare key - nothing.I am bloody furious -  I thought Japanese cars were supposed to be well made ?

 

PPS - 5 minutes later, try again and it opens. WTF is going on ? 

More than likely the key battery yes, they tend to only last around 3 years. 

Morning John,

Looks like a new battery is the ‘key’ to your dilemma. When the battery is below optimum the fob becomes lazy.

Try the second key fob and see if that works. CR2025 is the battery you need and is available at £ shops for, believe it or not a £. It is easy to replace, a quick search on the net will reveal all.Or if you are with us on Wednesday I will do it for you.

If you are having with the range and the key struggles to enable the starter, if I remember correctly Mazda advise you to hold the key fob against the starter button to turn it on and then press the button (check the manual), if that helps. Mind you if you can’t get in the car anyway that’s a fat lot of help! The short battery life is probably because key-less locking/unlocking means that the fob is nearly constantly transmitting which shortens the life of the battery compared to the plain old remote locking actuated by the button on the key fob. If you ask me key-less locking/unlocking is an unnecessary complication (and I do have it!).

There is a physical key in the fob for opening the door and then you can hold the fob near the button to start so you can always get in the car and start it with a flat battery.

My ND is almost three years old and I have recently had to replace the battery in the most used fob. I bought a pack of two batteries and have kept the spare battery in the car. Probably worth spending a little more on quality batteries rather than pound shop ones. A few pennies more for less hassle.

Many thanks . My better half is going to get me a battery later - hell I’ll push the boat out and get two. I will report back . See you Wednesday MM , hopefully in MX 5 and not my Yeti…   

Slightly concerning that the second key didn’t work either.  Could it be interference?  Consider that as a possibility if it only happens in one place.

I haven’t had starting problems, but my boot latch has refused to open on a couple of occasions both in response to the button and the plipper. The last occasion was on the way to Dover for an overnight stay before catching an early ferry en route to Italy (why do these things never happen at 9.30 on a weekday morning?)

I put my faith in it mending itself, which it had by the time we reached Dover.  I fully expect it to happen again.  I have since looked up the emergency opening procedure (7-55 in the online manual).

 

The battery in the spare key will probably be as old as the one in the fob you usually use. As previously said these fobs continuously transmit, so their battery life will probably be very similar. It may be an idea to leave the battery out of the spare key fob but keep it with it so that it is there if you need it. It will just eventually drain if you install it in the fob.

This is a dumb question I know, but I’m VERY hamfisted - arthritic knuckles.  How do you open the fob to change the battery?  Do you just “snap” it open along the seam, or is there a hidden catch or something?  Thanks!

A guide here: https://www.youcanic.com/guide/mazda-key-battery-replacement

Not a dumb question. First you take the key out. If you look on the back of the fob there is a little spring loaded latch which you pull back on in the direction of the arrow  using your nails or a small screwdriver, which allows you to pull the key out. Once the key is out you will see a small groove on the inside edges of the aperture where the key was located. You can use a small screwdriver in these slots to start splitting the case open along the seam and then use the screwdriver in the seam on the outside to split the fob along the remainder of its length. Once split you will see a round cover under which the battery is located.

  

Thanks Ian!  Very, very helpful!  

PS: And First Rider!

My Mazda3 has the same key system.  Both key batteries died within a couple of weeks of each other, after less than two years.  One lives in a metal filing cabinet so cannot talk to anything, the other is in daily use.

For a week or two beforehand the ‘multi information display’ in the dashboard should have been giving you an almost invisibly dim red message about the key battery being low (in the same place that the Service nag appears).

On mine the originals were Panasonic and when tested they had 3V as stated, but the momentary ‘short-circuit’ discharge current through my ammeter was almost zero.  I was impressed by the new Duracell which peaked close to two amps!

https://www.amazon.co.uk/gp/product/B003UP1OAM/

Very good video, changed mine without but nice to know I did it right!

Just to prove that I know lots of things, mostly useless, here’s what CR2025 means.

The first letter ‘C’ is the designation for Lithium batteries.

The second letter ‘R’ indicates the form of the battery as Round

The ‘20’ is the diameter in millimetres i.e. 20mm

The ‘25’ is the thickness in tenths of a millimetre i.e. 2.5mm

If you wonder what the difference is between a CR2025 and a DL2025 then the DL is manufactured by Duracell who just like to use a different code to confuse people.

See, Told you I knew lots of useless sh*t.

Thanks all. Sorted - I now have two keys which work as I found the spare was buggered too.Note to Mazda dealers - when you flog a secondhand ,3 year old, car then why not go the extra mile , spend two quid and replace the batteries as a matter of course ? And note to the editor of the huge handbook - err, why not say ‘replace battery’ if the key doesn’t work instead of 'consult your dealer '?

Where they have gone wrong in the manual is splitting the information into several sections. Yes it does say if you have problems with the keys consult your dealer. Then further on in section 3 it says if the key doesn’t operate change the battery as below. You do still have to go to section 4 to find the info on the warning light and then to section 6 to change the battery. Slightly annoying when you are locked out of your car in the rain!

It does say battery life is around a year so at nearly 3 years old I think we have got away lightly.

If the key does not operate when pressing a button or the operational range becomes too small, the battery may be weak. To install a new battery, refer to Key Battery Replacement (page 6-31).
Battery life is about one year. Replace the battery with a new one if the KEY indicator light (green) flashes in the instrument cluster (for vehicles with a
type A instrument cluster (page 4-39), messages are displayed in the instrument cluster). Replacing the battery about once a year is recommended because the KEY warning
light/indicator light may not illuminate or flash depending on the rate of battery depletion.

Glad you got it all easily sorted…

Just another angle on the spare key not starting the car, although in your case the battery was indeed flat…

If for example you unlock the car with your key, go back indoors, then wifey goes out to the unlocked car with the other spare key I’m pretty sure it will not start.

I’m sure I read somewhere that it will need to be started with the same key that unlocked it… with the Mazda 3 anyway…

 

Same thing happened to me this morning - car has just gone out of warranty. Boot would not respond to button or fob and same with doors. Used physical key to open door and car started fine with the key in my pocket. No problem when coming back to it tonight but I suspect the battery is about to fail. Fortunately I have a couple of new Duracells. Is there a time limit to replace the batteries? I know some will lose their code if you take too long to get the new battery in.

Thanks to this thread I have just replaced both batteries, car is 18 months old.  I didn’t rush it and had no problems, both work OK.  The manual makes no mention of a time limit.