any know what would cause this

[nos monkeys]

this is the first time it has happened but my flat mates mitsi eterna (galant type thing) its an auto and today and yesterday morning it starts fine as normal warmed up for like 10mins heater was cranking hot but when he hops in to drive as soon as he goes into reverse or drive the car turns off. it starts up fine straight away after and it is fine in neutral and park but turns off when he goes into reverse or drive, does it quite alot then eventually it wont turn off and hes able to drive off to work.

the last 2 mornings has been a frost not sure if that is why or not but during the day and coming home his car runs normal just the previous 2 mornings it does it and i dont really have any idea why .

surely the trans fluid wont be frozen? and surely the saftey switch in the shifter doesnt shut the car off i thought that just prevents the starter motor from starting the car if its in reverse or drive. these were the only 2 things i can think of.

thanks for any info.

[Subaru ETA]

Idle stepper motor faulty?

[nos monkeys]

i thought that when he told me but even if he revs it a little and holds it at 1000 then trys to change it just turns off, it fells more like it just turns off like when turning the key off rather than stalling out because of low revs

[evo1rs]

Not sure if this has the same systems but this is from the galant workshop manual 😊http://img.tapatalk.com/d/14/07/19/eza6u2yv.jpg

[nos monkeys]

Cheers, it may be the same system when i done a trans flush and new filter on it yesterday i noticed a plug which goes to some solenoid on the trans right next to the shifter cable so next time his car does it ill get up early and go out and have a look and play around to see if i can come up with anything, iv only heard it from my room because i don't really want to get up at 6am in the freezing cold just for fun haha

tomorrow we'l know if it does it again