mx5cartalk.com

Mazda USA are currently testing people’s cars and individuals have done their own monitoring and it would now seem likely that a fault in the RF’s cruise control causes it to generate 4 times the level of parasitic battery drain when the car is switched off with the cruise control active. This will cause an idle RF to completely drain its’ battery in 12-14 days. I know, I’ve had to jump mine 4 times already after coming back from business trips.

3 threads on miata.net on the issue...
https://forum.miata.net/vb/showthread.php?t=636758
https://forum.miata.net/vb/showthread.php?t=649014
https://forum.miata.net/vb/showthread.php?t=636758

In a poll on miata.net, 50% of RF owners responded that they’d had flat batteries already.

If you are an RF owner and have experienced this, I urge you to email Mazda Australia and at least register the issue. Mazda USA seem to be taking it seriously...probably due to the number of complaints they’ve received. Mazda Australia’s email is customersupport@mazda.com.au

In the meantime, if you are going to leave your RF parked for an extended period, turn the cruise control “off” before shutting down the car.

Why did you start a new thread for???
Old thread here where you already stated this.

http://www.aus-cartalk.com/forum/viewtopic.php?f=18&t=75023&p=923131#p923131

Because the title of the old thread was possibly too obscure and wouldn’t necessarily get the attention of RF owners. If the mods want to merge them and re-title the thread, I’m fine with that.

Mazda Japan have CONFIRMED the problem is indeed with the cruise control and requires the replacements of the RF’s instrument cluster! Hopefully a TSB will follow.

Not sure if Mazda has a single point of release for TSBs, but they do eventually get posted at following:
https://www.miata.net/garage/tsb/
https://www.truedelta.com/Mazda-MX-5-Mi ... s-175,2017

TSB for the battery drain issue

https://www.miata.net/garage/tsb/RF%20E ... harged.pdf

TieNN89 wrote:TSB for the battery drain issue

https://www.miata.net/garage/tsb/RF%20E ... harged.pdf

Yep. And subsequent advice I’ve had from Mazda Australia is that there will probably be a revision to that TSB. Apparently they are no longer going for a software fix but will be replacing the instrument cluster (albeit that, contrary to the TSB, they will be resetting the odometer to retain true kms).

Apparently the software fix that was being considered was likely to be changing the car’s functionality to default the Cruise Control to Off on shutdown. So more “workaround” than fix. Swapping the instrument panel is a proper fix.

My car is booked in for mid-Feb to have the instrument cluster swapped out.