99 V70-XC - new Transmission doesn't work

[Niamhsdad]

Hello all,
I recently replaced my transmission in my 99 V70-XC, it was so much more work than on my 850. Job went smoothly, and everything checked out well. I lowered the car, backed it out of the bay, let it idle to check leaks and such, and then nothing. There gear selector would move, but the trans wouldn't engage. not in any gear. I already posted about the possibility of a bad ABS module. So i bought on from Midwest ABS, got it in yesterday along with the old PNP switch from my old trans (just in case it was losing contact when warm). Still the same symptoms, after a few minutes when the trans is warm, it fails to engage. if i disconnect the neg. battery terminal, and reconnect it, i can put it into gear and it will move for a min. and then nothing. I am stumped..... Please tell me its something other than a bad trans. It is used from a local yard. (I have used them for years. there parts are always top notch). Another note. the front pan looks like it was removed in the past, there is red RTV slathered all over it. Thanks in advance for any help. I need this car to run. its my only ride.

[Matty Moo]

I'm going to assume that you've checked the atf level.

I had this exact same scenario unfold but it was only when it was below freezing. Jimmy57 posted something awhile back about something rubber in relation to the drums drying out/shrinking and adding a certain additive may help.

[Niamhsdad]

Thanks for the response, yes i checked the fluid... wouldn't that be nice, if that was it. Additive may help, however for $650.00 i want the trans to function properly. I think i am just going to have to pull it and hope the next one works. It comes with a 90 day waranty. I can't seem to come up with any thing else it could be. It works great when its cold, and then nothing.. so to me that says the TCU works, and the now the abs light is off so the module works. and the PNP is off my old trans wich i know was good. So aside from something inside the trans itself, what more is there that would cause it to fail when it gets warmed up?

[Niamhsdad]

Hello again, I contacted the JY and they drove the car with the donor trans in. So they verified it does work. I replaced the ABS module with one from matty moo and drove down the road. made it 1/2 mile and, no more trans at all.. It through codes P1618 and P0705. is there any chance its the internal wiring in the trans itself heating up and failing? I am at a total loss here.

[Matty Moo]

Thanks for the response, yes i checked the fluid... wouldn't that be nice, if that was it. Additive may help, however for $650.00 i want the trans to function properly. I think i am just going to have to pull it and hope the next one works. It comes with a 90 day waranty. I can't seem to come up with any thing else it could be. It works great when its cold, and then nothing.. so to me that says the TCU works, and the now the abs light is off so the module works. and the PNP is off my old trans wich i know was good. So aside from something inside the trans itself, what more is there that would cause it to fail when it gets warmed up?

I went through the exact same thing and it wouldn't trip any trans codes at all.

They gave you the exact same trans?

[Niamhsdad]

Yep, same trans. everything works great when cold, that is what trips me out on this. why would it work when cold then not when hot. Could it be the valve body and solenoid picking up old trans fluid goop? (read that on another forum). I know i'm reaching here, but i just don't want to have to swap out the thing again.

[JRL]

1618 is a communication error.
You may need to check every wire to the ECU or the TCU (not a lot of fun)

[FLXC90]

Before shooting all the wires, try disconnecting the battery, disconnecting, cleaning, and reconnecting the harnesses to the ECU/TCU, and the trans. (705 is for the PNP, so I would start there, maybe the plug isn't seated well, or row it through the gears a few times. Then do the reconnect in position II procedure (I have a 98, so I don't know the drill!)

[Niamhsdad]

I just tried to flush it per the instructions here. It looked pretty nasty. The thing is though, after the the second round of flushing, It just stopped pumping out the fluid. I need to know what to tell the salvage yard, is that the main pump, or could it be a valve body clogged. Thanks again. also, it didn't throw the codes until i got stranded down the road and kept trying to make it home before towing it.

[Niamhsdad]

For anyone who has been following this. I checked with the local volvo mechanic,(not dealer) and it turns out the main pump was failing when hot. I am back to pulling it and replacing it with yet another one.
Hopefully this time it will work as expected. I learned a great deal about auto trans that i didn't know.
Thanks for all the help.