Stop/ start and Transmission

[jewel]

The transmission on my 2015 Trailhawk shuddered when I stopped at lights in late November,it felt like 2 gears at once. Then it took off normally although the shift pattern changed. I then drove to the Sunshine Coast with no problems, except that the warning came up that stop/start was not working, it had not worked since the last tranny recall,I didn't worry about it. I took the car to the Maroochydore dealer who reset the transmission without any improvement. Took it to local dealer today and apparently the cause of all the problems is that the battery is on the way out, even though it starts first kick and ran a portable fridge to and from Cairns. Of course they had none in stock, maybe next week when the roads are open. Sorry for the long discourse, but I have never heard of a battery causing these problems.

[lujabe]

The battery died in mine with zero warning. Started first click, drove home. Parked in the driveway, then went to move it about 20 mins later, and nothing - except all the warning lights in the dash were going haywire. Though I never noticed any odd behaviours from the transmission (other than the usual weirdness..)

Got a new battery fitted by RACV same day - I shudder to think what Jeep would charge for one.

[jewel]

I was told battery under warranty for length of warranty, no cost to me.

[jewel]

The dealer said that a new battery would fix my transmission problems, I can understand it maybe fixing Stop/start, but has anybody got any ideas how this would fix the transmission problems?.

[Trailfirst]

Oh - I just realised that it's probably worth pointing out in reply to the OP's question about how the battery affects the transmission - that the Transmission is COMPUTER controlled, so naturally enough low or uneven power can make all sorts of weird stuff happen.

I've had a bit of a bite at Mr Cadogan on youtube over that - he was quite rightly bagging out the transmission BEHAVIOUR in the early model KL he was reviewing but slanging at the transmission design itself rather than recognising the issue was with the programming. Yes there was the bad batch of trannies with the circlip issue etc. but he wasn't dealing with a failed or failing trans - just one that was driving crap thanks to that early software revision they did to ALL KL's to mitigate the issues with the (relatively few) faulty transmissions.

We're on our second battery after original factory one died - ie. third battery over all. We took delivery of our TH in April 2015 - it was manufactured Oct 2014 - but I don't know when it was landed in Aus.

The factory battery death was signalled by climate control going weird - ie. setting itself to auto and full cold after one startup, then no fans after the next - otherwise it drove normally - altho yeah, at that time before latest trans software upgrade normal was pretty screwy anyway... This all happened from first start of the day until finally at the fourth stop my wife made in the course of doing her errands and shopping where it just didn't start. I don't recall exactly how long that was after we got the car - it was just outside the unlimited warranty but I'm not clear right now exactly when that was. Purpose here is feedback on signs / nature of the failure/s, not how long the batteries have lasted as such.

We bought a $280 battery from RACQ who said that was the correct spec for the vehicle.

That battery came with 24 or 36mth warranty but died a couple of months shy of the warranty - sorry, im too lazy right now to go downstairs and grab the current warranty card info for accurate dates. There were no clearly indicative symptoms until one morning it just wouldn't start. Everything seemed normal but there was just dull "click" when the start button was pushed. Remote start caused all sorts of strange dings and beeps and instrument display indications.

I'm thinking I did notice a couple of odd shudderings at traffic light stops in the couple of days leading up to it - I recall thinking shit I hope the trans isn't gonna chuck a fit soon.

I did normal troubleshooting sans multimeter or analyser - ie. earthing, battery connectors etc. - and it started fine when jumped from another vehicle. We drove it to the RACQ workshop who reckoned their analyser said no issue - however they graciously did replace the battery on warranty - but only gave us 6mth on the replacement... Needless to say that in spite of the idiot "expert" assessment, it hasn't skipped a beat since the new battery went in (November last year I think).

I'm an aircraft mechanic and deal with high capacity 24V Lead Acid batteries in the particular planes I mainly work on at the moment (powered by PT6A turboprop engines). The bastard things are a real headache and one company I worked for found the safest way to maintain reliable operations was to just fit NEW batteries every 12 months... We used to use the removed batteries for external power supply during maintenance or for external power starts - some would last YEARS happily while others would crap out within weeks (headscratch).

Batteries in my EF Falcon used to die also suddenly and with no warning at 2 years like clockwork.