Car help needed

[98brg2d]

You need to find a good impreza/crosstrek forum to figure out exactly what could have been damaged. Most auto/CVT subis have 3 main computers that are connected and each can cause problems - ECU, TCU and BIU (body integrated unit). Some information is passed through the gauge cluster as well. Some subi dealers have issues with programming vins into BIUs and stuff like that. If they tell you something like that, may be best to find a different dealer, if one is near you.

If you get the car back and it is still giving issues, start tracing the grounds and see if one is missing or disconnected or dirty. That is where I would start and can be done at home easily enough and the dealer may not even check that if they aren't following the fault analysis steps in the FSM, they may assume they are good based on the mileage of the car.

[MontuckyFried]

I suppose the transmission could have been ready to throw codes and require repair. It wouldn't be the first time something failed startup because of a failure somewhere else.

True, but personally I like to try and rule out all vastly cheaper possibilities first. I've been quoted thousands by dealers before for this that and other when all was resolved with a cheap fuse/relay/module/battery. Or when I was told I needed a new alternator (an $1800 fix I was told) when the problem was ACTUALLY a worn out belt that needed changing.

Sure, the transmission COULD have issues, but I just don't trust dealers at all. Sucks we have to depend on them for fixes requiring dealer-only computers, though.

I get seriously annoyed because I'm a shade tree shmoe who shouldn't know nearly as much as the trained specialists at the dealers yet I seem to diagnose more accurately than they ever do. Perhaps they're spoiled by manufacturer warranty work where they can just replace major components willy nilly. "Car's idling a little funny. BETTER REPLACE THE ENGINE!" "Your car threw a trans code. BETTER REPLACE THE TRANSMISSION!" It's nuts.

[4matic]

Dealers warranty their work so they can't risk uncertain repair. I get that and my indy mechanic sends me to the dealer for some repairs.

[fatnslow]

I don't know the mechanical capabilities of the op or how long he can have his car down but if that was my car I would get on a Suby forum and start doing some research and look into sourcing a used TCM and hot swap that thing IF it doesn't require any dealer programming. I think the CVT units are a bit of a black hole with most transmission shops beyond a routine fluid change or replacement. Look into if that car has limp mode and what it takes to reset it as well. Keep in mind that most dealerships WILL NOT fuck with transmissions beyond replacing it due to the high frequency of return visits it can create.

[MontuckyFried]

Also forgot to mention to check the battery cables! I had some funky codes thrown last year where no issue was obviously present and was getting a bit of odd battery drain. Ends up it was a corroded battery cable! About a $50 fix and all was resolved. Anyone else think it's possible that the battery swap mistake could have melted/corroded something internally there?

[fatnslow]

Also forgot to mention to check the battery cables! I had some funky codes thrown last year where no issue was obviously present and was getting a bit of odd battery drain. Ends up it was a corroded battery cable! About a $50 fix and all was resolved. Anyone else think it's possible that the battery swap mistake could have melted/corroded something internally there?

My guess is that either ecu or tcm has some damage from the polarity reversal. Doesn't require much to damage a capacitor before the main fuse blowing UNLESS the op was ignoring a cvt tranny that's been whining and shifting funny for a bit. I would think the first thing the dealership would inspect in this situation is the battery, ground and charging. The test devices that shops use for battery health is pretty comprehensive that will check the electrical system. I just had a battery shop check my car with one and it was able to check battery health, alternator charging capability as well as the starter. That should help eliminate grounding and dc supply/source issues.

[montanaskier]

Car has 150k....they kept the car to run diagnostics to see what could be happening including TCM and ECU. No word today yet.


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[ill-advised strategy]

Perhaps one of us knows a trustworthy shop where you’re located.
Where is this all taking place?

[montanaskier]

Perhaps one of us knows a trustworthy shop where you’re located.
Where is this all taking place?

I live in the Vail valley. I know a bunch of good shops but I took it to the Subie dealership in Glenwood because I’ve purchased a bunch of cars from them and they always given great service. This experience hasn’t been as great mainly because they don’t seem to know what the problem is yet. We’ll see what they say tomorrow.


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[snowaddict91]

The biggest thing you are up against is service advisors suck at listening. They probably ignored you talking about the whole experience and are going to tell you the tranny is bad.

Personally, I don't believe in coincidences. If your transmission was working fine before this failure, its almost certainly electrical/computer related.

[montanaskier]

Changed the main fuse again as well as some other fuses and I’m back to normal. What a weird deal


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[snowaddict91]

Changed the main fuse again as well as some other fuses and I’m back to normal. What a weird deal


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Glad to hear it!

[ill-advised strategy]

Nice.

[stealurface831]

okay, so my 2007 suburban is in the shop at the moment. i am getting rid of it either way but the oil pressure is low while idling but it corrects when driving. the dealership techs are trying for an engine rebuild to replace the bearings which seems absurd. if there was significant enough bearing clearance to cause low pressure, wouldn't it be the same whether driving or idling? anyone else had this problem before? my google readings say that simply getting a higher viscosity oil may do the trick. that seems too intuitive. anyone else had this problem or tried a higher viscosity oil to fix it?

[snowaddict91]

Could be pressure sensor or oil pump failure. The higher viscosity thing is just a trick to get rid of it on trade in or something. If that fixes it you are just masking until a major failure down the road.

[stealurface831]

Could be pressure sensor or oil pump failure. The higher viscosity thing is just a trick to get rid of it on trade in or something. If that fixes it you are just masking until a major failure down the road.

that begs the question, how ethically wrong is it to pull that trick for a trade in?

[snowaddict91]

that begs the question, how ethically wrong is it to pull that trick for a trade in?

Trade in to a dealer? I'd have a clear-ish conscience, car dealers are mostly assholes. I'd never think of selling private party like that though.

[Mazderati]

The oil pump is an issue on some LS engines. May be able to replace it and keep going without any other problems if it hasn't been driven that way for long.

[Timberridge]

Oil pressure is highest on a cold start and subsequent idle and goes down once the oil is warmed up. You have the opposite problem. If your hot idle pressure is higher, it could be as simple as a leaky valve cover gasket that seals up when things get hot and expand.

Go thru all the simple stuff first like oil filler cap seal, breather hoses, pcv valves, clogged oil pump pickup screen, etc. before assuming the worst.

Or just buy the FJ.

[wooley12]

If I was selling it

I'd go to the aisle at NAPA where they sell oil additives. Look for the ones that say "MIRACLE and GUARENTEED on them. Get the one in the red container if you can. Buy two and follow the directions. List the vehicle.