PNP question 96 850GLT

quarl · Post by **quarl** » 04 Jun 2011, 16:08

I have a strange issue with my PNP and it doesn't seem to get covered in all of the copious posting on the subject. I'm hoping for a little insight.

I put a used engine in my 96 850 using the great writeup on this site and it works like a dream. But now I've got the dreaded flashing arrow on my dash. The tranny never showed any sign of trouble before the swap but now I can't get the darn thing to stop flashing.

I've taken the PNP apart, cleaned it and relubed it with dielectric grease. I've adjusted it about thirty times and reset the shift linkage a similar number of times, also using the fine instructions on this site.

Thing is, it shifts fine (although a little slow to shift out of first while cold). The reverse lights work fine and the fluid is topped off with new.

I used the tweezer technique from this site and tried the trick with the mirror on the reverse lights but couldn't get them to go off no matter where the switch was positioned. I wonder if that has something to do with it?

I'm at wit's end on this project. I've got about $1500 in the new motor and my wife is not happy with the idea of me spending another weekend in the driveway. Hopefully, there's something simple that I've overlooked...

quarl · Post by **quarl** » 04 Jun 2011, 16:24

In reading (again) posts on the subject, I realized that I should mention that I can start the car in both park and neutral.

quarl · Post by **quarl** » 05 Jun 2011, 07:09

Maybe I should also add that I did the "ratcheting through the gears" technique when the arrow first came on and it made the light go off for a day or so...

mdvolvo · Post by **mdvolvo** » 05 Jun 2011, 07:13

maybe your problem is not the pnp but the vehicle speed sensor.
did you try checking for codes?
Is the check engine light on also?

quarl · Post by **quarl** » 05 Jun 2011, 08:13

Yeah, the CEL is on (why didn't I think to include that little nugget?). But I believe it was on when I started the car after replacing the engine.

I don't have an OBD-II reader but could easily get one. However, I read somewhere that the tranny codes weren't stored there, and that I'd have to buy an expensive unit to be able to reset the CEL so I figured I'd just take it down to a local garage that can give me codes and reset it.

FCP has an entire page of "speed sensors", most of which are ABS related. Are you talking about what they call the reference sensor (rpm sensor)? http://auto-parts.fcpgroton.com/speed-s ... -model-850

If it's the "crank position sensor" that bolts through the top of the bell housing, I just happen to have a spare from my old engine. I suppose it's possible that the old one is bad, the previous owners took it in to the shop and were told it'd require a new tranny and so they scrapped it. Lemme just go ahead and swap it out and see...

Post by **erikv11** » 05 Jun 2011, 08:47

I'd definitely start with swapping around the rpm sensors.

The thing about the reverse lights and starting in neutral, that does sound like a PNP problem, but not the rest. Did you use copper contacts in pretty good shape when you rebuilt the PNP?

quarl · Post by **quarl** » 05 Jun 2011, 09:07

Swapping the sensor had no impact on the blasted flashing arrow.

quarl · Post by **quarl** » 05 Jun 2011, 09:10

The contacts were in good shape. One of them, the one closest to the driver, was a little rounded. I filed it down a bit and used it in the middle position since it only has to make two simple contacts.

quarl · Post by **quarl** » 05 Jun 2011, 09:14

I've read a few different posts about how some people are able to get the reverse lights to come on in both directions of turning the PNP, some people can only get it to come on in one direction and some, like me, can't get it to go off. That seems a little squirly to me as a reliable guide for setting the position. Does it also seem to suggest anything about the condition of the switch itself?

Thanks for the input. I have to go out for a family function so won't be around the computer for the rest of the day.

quarl · Post by **quarl** » 05 Jun 2011, 16:02

No quick fix yet? Bummer!