2001 S80 Transmission Issue

biw1428 · Post by **biw1428** » 09 Sep 2012, 22:49

Hey guys! I'm new here, and have quite a bit of experience working on Volvo's, but I have gotten a fixer-upper S80 for a heck of a price, and it has me stumped! There will be a link to a youtube video of the car acting up after this. Here's the story: The car is a 2001 S80 T6 with the 4T65EV-GT in it. It's got 118k miles on it, and when under light acceleration, or maintaining a speed between 35 and 45 it seems to slip out of gear. Here's the funny thing though, up hills, or above 20% throttle, it shifts every gear fine, every time. Turning Traction Control off also makes it do this less, which makes me think a computer problem. I do know the car has a gutted catalytic converter thanks to the previous owner, although I don't believe this would cause the shifting issue.
The car has NO Transmission codes or STC codes.

Already Done:
Fluid+Filter change (Made No difference)
Replaced a Brake Position Sensor

Youtube link is the actual car in question.

Thanks a bunch for help, and I'll be around for sure in the future!

Post by **boosted5cyl** » 10 Sep 2012, 11:36

Thats pretty weird. When you say no trans codes, was the trans controller actually scanned with VADIS/DICE? I might have said torque converter lockup but Im not sure if it should lock up under those conditions or not. Been a while since ive driven my S80! I'm not a transmission expert but I know a little.
Have a look through VADIS and see if there is a lockup solenoid test procedure.

Post by **Volvoforlife2** » 06 Nov 2012, 09:04

Hello All,

I drive a 2001 volvo S80 and hava a transmission service light on. This is what happens when driving; From a stop position, the gears will shift nicely but if slow the car down in a highway below 40kph, the transmission gets stuck in 3rd gear. I have changed the filter and fluid and i do not know what else it could be. But it is interesting you talk of the brake position sensor, what does it contribute to a malfunctioning transmission?

Steven

biw1428 · Post by **biw1428** » 18 Nov 2012, 19:55

So, I ripped the trans out, and it's just worn friction material. Time to replace it! Going to get a guaranteed unit and swap it in myself.

Steven--That "stuck in 3rd gear" you describe is actually the car's built in failsafe, or "limp mode". It locks itself in one gear to prevent further damage to the transmission. I wouldn't say rebuild/replace it without first seeing if it's an electrical problem. The shift solenoids in the 4T65's (the transmission in these cars) are known for going out as well. Much cheaper than a rebuild. Best of luck!

Post by **Volvoforlife2** » 21 Nov 2012, 03:36

Thanks biw, forgot to add that when the transmission gets stuck in 3rd gear, i have to pull off the road and stop engine for something like a minute. From then on, i start the car again and it often shifts nicely to the last gear (4th) and i can even go for 400km that is if i dont get traffic that will slow me up to below 60kph. What is this electrical problem that you mention is it a bad battery or somethjing else-Still on this my reverse assist beep does not work anymore (electrical possibly). Somebody did a diagnostic for me not so long ago and it pointed to the brake pedal position sensor which is why i ask does it have anything to do with the transmission. I also had an incident when the transmission service urgent light just disappeared only for it to reapper after a month

strange.