Hi all,

after installing a sub + amp, the auto trans in my TJ magna has stopped working. The battery was disconnected during the install and now the car takes off in a high gear and does not change out of it. It is extremely slugish as you could imagine.

The Sequential shifting does not work either and none of the dash lights light up to say what gear your in etc.

Any help would be greatly appreciated.

thanks

Check the fuses under the dash and the fusable links in the engine bay first. If all is fine
then it sounds like a short circuit somewhere. Are you sure you wired your amp and sub
correctly?

positive,

im an electronics engineer by trade and there are no short circuits, everything is appropriately grounded and from what i could tell in the dark, all fuses were operational.

positive,

im an electronics engineer by trade and there are no short circuits, everything is appropriately grounded and from what i could tell in the dark, all fuses were operational.

From experience, something is messing with the ECU/TCU and causing it to go into fail safe
mode. The alternator on my old KS was on its way out and every so often (every 30 mins
of driving) it will cause the TCU to lock the gears in fail safe mode. It does not take much
to trigger this.

What else isn't working? Need to narrow this down. Does it idle? Can you select neutral and reverse? Headlights work?

When it was on idle at first, as soon as i reconnected battery & started the car, the idle was raeally low and stalling, i kept the rev's up and drove around the bloke a few times. Fixed the problem. i was thinking alternator at that stage.

Reverse works fine along with all the other electronics in the car. Something in the ECU possibly? Or as Vlad stated the alternator heading out?

When it was on idle at first, as soon as i reconnected battery & started the car, the idle was raeally low and stalling, i kept the rev's up and drove around the bloke a few times. Fixed the problem. i was thinking alternator at that stage.

Reverse works fine along with all the other electronics in the car. Something in the ECU possibly? Or as Vlad stated the alternator heading out?

My battery died - gave nothing. Replaced it, had the failed battery tested - tested fine. But was doing a similar thing so I thought maybe the battery connections on mine were suspect due to my constant underhood fiddling, but your alternator just might be crook. The hi-po sound system taking the last breath of life from the battery perhaps?

I had some weird occurances myself after my sub+amp install, because my ECU reset my car forgot how to idle and I had to sit it there for half an hour at one stage just to retrain it so it would stop stalling. I only did this recently so it is slowly re-learning my driving style, however it seems since the ECU was reset my fuel economy increaed by about 100km/tank so I guess there was a plus side afterall. Still a little rough on shifting though getting better.

i know you said that the dash wasnt lighting up to tell you what gear your in, but is anything flashing in the dash?
P/N/D?

i think if N or D is flashing it means the tranny has gone into limp home mode on the 3rd gen?

sounds like it is in limp home mode by it locking out the gears but im not sure as the cause...

im not much help i know...

I've had some weird things with dying batteries, but never limp home mode. The NRMA guy that replaced my last battery said only Magnas are strange after battery changes, due to the 'learning' having been 'forgotten' (I'd imagine this is only TE- though). He made sure it worked before I left, and it kept conking out for the first few minutes

check the mini blade fuses under the drivers side kick panel.. it's a random fuse so don't go looking specifically for 'auto trans' or anything like that.. i think it has a fog light picture that correlates to the fuse... i know it sounds weird..

mat