95 850 transmission problem

elchopperfreak · Post by **elchopperfreak** » 17 Aug 2011, 18:45

Hi, im posting this for a friend, his 1995 850 volvo is having transmission problems, when cold, the trans works and shifts fine, as soon as it warms up, the arrow starts flashing and the car loses power, trans bogs it down. He lets the car cool again and it works, just to repeat the symptoms..
Any help, ideas..
Thanks guys

Post by **Ozark Lee** » 17 Aug 2011, 18:52

My guess is a PNP problem but codes from port A-1 will help.

...Lee

elchopperfreak · Post by **elchopperfreak** » 17 Aug 2011, 19:00

What is the pnp? Is that the trans sensor?
Could ie be the trans is fried?
Thanks for the prompt response

Post by **Ozark Lee** » 17 Aug 2011, 19:50

The PNP is the Park-Neutral-Position switch. It is actually more than that as it determines what gear you have selected (or it thinks you have selected) and if it says one thing and the transmission says another it basically punts and goes into limp mode with the flashing up arrow and you are stuck in 3rd gear.

In some cases the switch is just flat bad but in other cases you can adjust it to make things work properly. The adjustment is critical and MIJ has a writeup in the repair database that details how to adjust the switch, with no special tools, by using a mirror to look at the reverse lights as you adjust the switch.

The PNP itself isn't that big of a deal to either adjust or replace as opposed to the transmission itself which is a big deal in both the parts and the labor involved.

...Lee

elchopperfreak · Post by **elchopperfreak** » 17 Aug 2011, 19:54

Excellent!!!
Where is it located?
Thank you

SRG850 · Post by **SRG850** » 29 Aug 2011, 03:49

You are far from alone. I hopped in my '97 850 yesterday and as I cranked the car, it revved high (first time in years) and I put it in reverse...instant flashing yellow arrow. Well, I went two blocks to the store, all was okay. When I came back out, car started and went into "limp home mode". Will try the "shifter" method for a quick fix, and post here later. I have found this site to be a godsend when it comes to the eccentricities of the beast known as Volvo.

elchopperfreak · Post by **elchopperfreak** » 29 Aug 2011, 18:54

My 850 is doing the same, but after a bit, i guess when it warms up, but alas, my in the radiator cooler was leaking fluid into the trans, still flushing, the trans works fine until the arrow lits..
The friend I started the thread for decided not to buy the car..
Can the PNP be cleaned??

Post by **erikv11** » 29 Aug 2011, 23:04

There is a writeup in the repair database about how to clean the PNP. It is a very good and clear writeup.

The problem 99% of the time is worn copper contacts inside the PNP. You've got a parts car, right? Take the PNP from the parts car, open it up. Take out your PNP, open it up. Find the best 3 contacts of the 6 you will now have in front of you, put it back together, reinstall in exactly the same place, you will be good to go.

Here is the link from when I did this: https://www.matthewsvolvosite.com/forums ... 1&p=105245

I also recently saw a post here, that some online place is selling a "PNP rebuild kit" for these cars. The kit contains the 3 copper contacts. It is $20 which is too high but way cheaper than a new PNP. Do a search on this site if you want to find that.

elchopperfreak · Post by **elchopperfreak** » 29 Aug 2011, 23:33

Thanks Erik, will check it out, although the code shows something about the trans input speed sensor..
Will have to locate this sensor in the trans and try too, although one at a time to pinpoint the problem.

elchopperfreak · Post by **elchopperfreak** » 29 Aug 2011, 23:41

Cant link to the DIY?