- My model of MX-5 is: __30AE
- I’m based near: __tamworth
- I’m looking for technical help or recommendations on: warning battery malfunction pull over when safe to do so flashed up on info screen. checked on board warning screen nothing showing, this has happened before about 3 months ago and just went away. have also had a friend check for faults with his reader no errors displayed. Any ideas would be appreciated.
Hmm, just an off-the-wall thought, but I assume you have physically checked the battery terminals are correctly done up and secure?
Give them a gentle wiggle - they should not move at all.
And remember it’s four tabs to release when removing the battery’s plastic cover; two marked, two unmarked on the other side.
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I also have an ND 30th Anniversary and yesterday experienced the same Battery Management Malfunction message with i-stop light flashing. You say it went away before - did car drive OK etc whilst error was showing and how long did it take to go away please ?
First is to check for errors via the OBD socket. If it shows no errors remove the earth battery terminal for 15 minutes and then reattach to see if this helps. (There is no battery cover on ND cars)
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I’d suggest that it’s probably a stop/start battery which could be an AGM type.
It’s 4 or 5 years old and maybe getting a bit tired.
If it is AGM, then they are supposed to be maintenance free, however, the fluids can still evaporate over time, which leaves the glass mat dry.
On my Kia Sportage.
I scoured the web for advice, some said you can’t top them up, others said you can.
Considering mine was probably on its way out anyway, I took the risk and topped it up.
It gave the battery a new lease of life.
It is not am AGM, it is a ‘wet’ battery and you can top up each cell if it is low.
Quick re-cap on my issue: had battery warning about 3 months ago car drove fine problem went away. Same warning came up again recently once again car drove fine and issue went away. A mate used his OBD no warnings found. Took it to main dealer to try and find out what is going on is it serious. Dealer did full electrical health check all good But did get an error code P0A8D relating to low voltage? Battery good all associated electrics good, they said this problem has been seen before and is probably just a gremlin nothing to orry about. Not totally convinced but driving to Dorset on saturday so will see what happens. I suspect the istop is at fault and ill switch it off, Bonus the dealer did’nt charge anything for their work (did buy car from them). Many thanks fr all good feedback, watch his space for updates.
The saga continues: Drove to holiday in dorset about 220 miles no issues, car behaving as expected. 3 days into holiday driving along coast about 11 miles got Battery Management System Failure plus:
iEloop system malfunction
iStop system malfunction
LDWS malfunction
SCBS malfunction.
Stopped car onboard system registered the above faults. Switched engine off re-started no faults showing. Drove back to holiday apartment no warnings no issues. Few days later drove home 220 miles about 3 hours driving no issues car drove perfectly. Done about 50 miles since mostly town driving no issues. Any ideas Software refresh maybe bit concerned this may be the strart of something serious. Any suggestions much appreciated.
That is a bit concerning.
I would remove the negative battery terminal for 10 minutes, it will not do any harm but may reset everything and it is free.
It would be a good idea to have the software updated at the next service as well.
Has the stop start been working?
Please keep us informed of any further developements.
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Start/Stop seems to have a mind of it’s own works intermittently. Will try removing neg terminal good tip. Thanks for the feedback, watch this space.
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Same thing happened on my 2019 2.0 litre ND. I got the warning as previously mentioned telling me to pull over when safe to do so. The iStop had been working fine prior to the message and the car was driving fine. If the battery was not charging enough the iStop would have not been operating. I pulled over and turned the engine off and restarted it (reboot 
). Problem gone and not returned so far. Did the OBD analysis and no faults found.
Some time prior to this I had a warning that the Blind Spot Monitoring System had a failure. Turned the engine off and restarted. Warning gone and BMS working fine. Did the OBD analysis and no faults found.
I am not going to worry about it as reboots seem to get rid of the warnings. If the faults reappear straight after or not long after a reboot I will then take the faults more seriously. Possible some sort of software bug or “anomaly” as the Post Office would say.
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Does not fill me with confidence spurious warnings do not bode well. The garage (main dealer) said it was probably just glitch so will just have to wait and see.
Did you get anywhere with this? My ND has been suffering intermittent battery management system warnings issues and also an intermittent engine start issue where the engine judders violently and stalls when starting after it has been at operating temp, stopped for 10 to 20 minutes but then restarted when it is still warm, say after a visit to a petrol station. Not at the same time though. In the case of the battery management system warning, a restart of the engine clears the warning and the car drives normally. In the case of engine start judder and stall, it starts at the second attempt fine.
My OBD11 diagnostics tool always shows “No Code Found” when checking for any DTCs. In three visits my not so local Mazda dealer had no luck in determining what is causing the judder and stall on warm start up but on the last occasion found a stored (not current) error code of P2502 - “Charging System voltage”. They are surmising that it could be that the alternator is “sticking” i.e. temporarily seizing due to a faulty bearing or such like! They also think that this may also be linked to the engine starting issues. I find this hard to believe and think that it is far more likely that there is a connector in the system that is suffering from an intermittent contact. This has so far cost me a fortune in diagnostic charges and the issue is still not resolved. The dealer has asked me that next time I get the the “Battery management system fault warning”, I should stop the car, not attempt to restart it, but call out my breakdown service to have the car transported to the dealer (not exactly convenient especially if in the middle of nowhere at night).
Is anyone else suffering similar problems or have any idea at all what the problem might be? I would be very grateful for any advice.
Many thanks.
Still got the “battery Malfunction issue” very intermittent. Since my last post in june has only happened once 3 days ago. Battery malfunction flashed up, stopped car and on checking onboard error system it showed Battery malfunction and istop malfunction. Carried on home checked error message log nothing there. Car has had full battery/electrics check at main dealer all no issues. The car drives fine when errors flash up, i have switched of itsop etc. hope it does not one day be more problematic but not sure what else can be done. Fingers crossed and just bought a st christopher medallion lol
I have looked at the online manual DTC P2502:00 [PCM (SKYACTIV-G 2.0)] | 2016 ND Shop Manual (hexorcism.com) relating to the recorded P2502 DTC the dealer found and it says to check all the connectors in the charging/Battery/PCM system before checking the alternator. This is the first thing I would have done but when asked the dealer said the system had not detected an open or short circuit. But, what if it is just a dirty/poor connector contact or fractured wire that causes an intermittent open circuit problem. I am gob smacked that they did not check for this. I think that I am going to take a look at it myself if the job looks reasonably easy to do.
Update. I have taken a look and it is impossible to access and check the PCM system connectors as suggested in the online ND Shop as access to the PCM connectors is prevented by a tamper proof guard! If anybody has any look at getting these intermittent Battery Malfunction Issues resolved please let me know as I have completely given up with the Mazda dealer. They don’t seem to be willing to do the connector checks as I requested. Instead they have suggested changing the Alternator which they told me may be “sticking”!
Just out of interest have you tried taking the battery negative lead off for 10 minutes and then reconnecting.
I know it’s an old trick and may do absolutely nothing but it is free.
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Hi Malc,
Yes I have taken both the positive and negative battery connections off and cleaned them up. Battery connections are one of the areas the manual suggest to check as well as the alternator and PCM connections. I don’t know if it has worked as I haven’t driven the car since and the problem is intermittent. Cheers.
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I had random issues as above, in the end I changed the battery and all the issues disappeared. istop,which hadn’t worked consistently for months, suddenly started working again.
Even now, if I don’t use the car enough (my bad) and the battery goes a bit low, I will get non-iStop mode but disconnecting the neg terminal for 15 minutes cures it.
I now connect a 20w solar panel if I know I’m not going to use the car for a week.
BTW, putting the battery on a CTEX often results in an istop error as the battery voltage monitor and the internals argue about what is right and wrong; disconnecting the neg terminal fixes it.
I’ve got so used to disconnecting the neg terminal I now use this; £6.99 on Amazon. Saves hunting for a spanner.
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Hi Jeff,
Thanks for your advice. I wouldn’t call it random Issues that I have, but the same issue that happens intermittently, if you catch my drift. I would have hoped that the dealer would have checked my battery if this could be the cause of my issue. When this DTC P2502 fault has occurred the i-Stop function has been working normally. I wouldn’t have thought that i-Stop would work if the battery was not charged fully and operating correctly but it is worth considering. In my experience these intermittent repeated faults are nearly always caused by poor or broken connections/wiring.
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