PNP switch, solenoid 2, flashing arrow, limp mode-'94 850

Mike850 · Post by **Mike850** » 10 Jul 2008, 16:08

disclaimer: I researched and read many forums first, before deciding to create this topic. But I'm not completely satisfied with what I've found so far. Therefore I would like to solicit advice from the experts.

Background:

A few months back the orange "up" arrow on the dash began flashing indicating a "fault in the automatic gearbox". However the car was not stuck in 'limp mode" and everything seemed fine. Soon it went a way.

Months later, after a lot of stop and go driving while stuck in a traffic jam due to a wreck in "rush hour", I began smelling a burnt smell. The flashing arrow returned and limp mode enabled. I found I could manually shift gears so I could take off in first, ect. After some time (and ratching the gear shifter 15-20 times to clean the copper contacts) the arrow went away and the car drove fine (classic PNP safety neutral switch going bad sympton).

Recently, the arrow came back on and was again stuck in limp mode. Manually selecting the "L" mode would allow me to take off in 1st and then I would move it to "D". Then about a week ago it got where it wouldn't even go into 1st gear even with the gear shift selector in "L". So now it was permanently stuck in limp mode and taking off in 3rd gear.

Last weekend I replaced the PNP safety neutral switch. Bay 13 has good instructions on how to replace it: http://volvospeed.com/Repair/pnpswitch.php
I aligned it myself without the VOLVO tool by ensuring the brake lights were on when the gear selector was in "R"using the following helpful link found in this forum: https://www.matthewsvolvosite.com/chat/p ... 7963#57963

I cleared all codes and test drove the car. No codes were thrown except for one in the A-1 (transmission) socket which was 2-2-2, "S2 solenoid open (main relay signal absent or faulty)".

1) If I didn't quite align the PNP switch perfectly what would happen? (The brake lights come on when the selctor is in reverse...but when shifting halfway between reverse and park, the lights go out while it's still in barely in reverse.

2) Can the S2 solenoid in the transmission be replaced without dropping the subframe? Any good instructions available for replacing this solenoid?

Presently I am driving the car in limp mode. My wife needs here vehicle. I am timing stop lights and rolling through stop signs, parking on hills ect., and take it very easy. So far no burnt smells. As always, Any advice is greatly appreciated my friends.

Post by **JRL** » 10 Jul 2008, 17:12

If you haven't already you're going to blow up your trans.
You CANNOT keep driving this way.
The "rowing" is just to get it working TEMPORARILY until the PNP switch was replaced SOON, you did not do this and most probably did permanent damage to your transmission

Mike850 · Post by **Mike850** » 10 Jul 2008, 18:26

Thanks, but I acted as quickly as possible. I still had to drive home from work, ect. When it went into limp mode, I parked the car at home, borrowed a vehicle for a week and ordered the part online through FCP Groton and installed it last week. So I acted on it as soon as I could but "soon" is a relative term. It's hard to say whether or not I was able to park it and act soon enough.

Regardless, the PNP Safety Neutral switch was replaced but the arrow is flashing, it is stuck in limp mode and the only code is 2-2-2 referring to the S2 solenoid.

My guess is two possible solutions:

1) Remove the battery, air box, and all that other stuff to access the PNP switch and try re-aligning the PNP switch to make sure it is exactly aligned. I've read it has to be aligned within 3 mm or it won't work. Does this sound like a possibility? Even though the brake lights are on while in Reverse, the lights go off at the halfway point between shifting between Reverse and Park with the transmission still engaged in Reverse. So that's why I ask does this sound like it is slightly out of alignment?

2) The S2 Solenoid could be bad.

I'm not a quitter. Ratter than throwing in the towel and giving up on the transmission I want to fight this battle. If anyone has constructive advice, including how to replace the solenoid I would appreciate it. Thanks.

chuckcintron · Post by **chuckcintron** » 10 Jul 2008, 20:35

The first/easiest thing to do is make sure the alignment is correct on the PNP. It can make the car seem possessed if it's not aligned correctly (although you usually will throw a 3xx code). I really doubt this is your issue, but since you touched that part you should go back and validate that it is aligned.

Next, just in case it's your turn to win the lottery, do a simple drain and refill of the tranny fluid (some people will tell you to flush it, but at this point I wouldn't risk that). On rare occasion that can 'fix' a bad solenoid.

If you still get the 222, then the S2 solenoid is toast...and hopefully the transmission itself is not damaged. I've not done this myself, but I believe you need to lower the subframe to get to the solenoid cover. EDIT: read here for someone who did it a much smarter way:

https://www.matthewsvolvosite.com/chat/p ... hp?t=12985

I also hate to say this but if S2 is shot, S1, SL and STH are probably not too far behind. Low pressure may have been what predicated all of this. You didn't say how many miles you have on this car but you may be at the point where a rebuilt transmission is a safer bet on this repair. Hopefully the first two easy steps above will be all it takes and you don't have to make that decision.

-Chuck

les & reilly · Post by **les & reilly** » 18 Jul 2008, 19:05

as someone suggested already.
i would agree to setting the pnp in its right place, as your brake lights should not come on when you move the lever.
from reading between the lines, i dont think your s2 solenoid is gone. i would also suggest changing the tranny oil if you have smelt burning.
i currently have a problem with my s80 t6 geartronic and have been unsuccessfull so far in a repair, but have not give up yet (because i know if someone pinched it, they would only bring it back and dump it in my driveway!)
the 850 auto box is far more basic compared to mine, and i wouldnt think you would need to remove it or replace it. it is possible that s2 solenoid is sticking because the oil isnt good.
also, i believe on the 850 autoboxes that there is also another microswitch which often goes wrong and this is under the gear selector lever.
it might be worth you replacing that for peace of mind as it isnt too difficult and it isnt too expensive.

Mike850 · Post by **Mike850** » 21 Jul 2008, 17:38

Chuck/Les & Reilly:
Thank you both for the constructive feedback and advice.

I also wondered about the microswitch under the center console as being a possible suspect. It's called a "gear selector micro-switch" and FCP Groton sells them for $23.05. Secondly, changing the fluid (even though it is still red on the dipstick) is probably a good idea since I smelled burning once and it could even free up a "sticky" solenoid??

Due to the fact that the only code that has been thrown is 2-2-2 (code for S2 solenoid) makes me think that S2 might be the likely culprit over a mis-aligned PNP switch. (The brake lights DO come on when in reverse--they just turn off when shifiting into park BEFORE disengaging out of reverse). I ordered a new S2 solenoid from FCP Groton just in case and received it last Thursday, but didn't get the opportunity to touch the car over the weekend. The solenoid is much smaller than I had pictured at only about 1 1/2 inches long (and costs $105)!

But since many of the same items must be removed anyway (battery and tray, intake hose, ect.)--whether accessing the transmission solenoids or PNP switch it makes sense to first double-check the PNP switch for exact alignment before proceeding to the transmission. I will post the results and hopefully this will help someone else out there that still gets the orange arrow even after replacing the PNP switch.

Mike850 · Post by **Mike850** » 31 Jul 2008, 02:55

BTY, the car has about 150,000 miles on it. OK, here are the results:
1) PNP neutral safety switch: I took it back off and then re-installed it to make sure it was aligned correctly. It was and the brake lights come on in reverse like they should. So no issues with the switch.

note: to make clear, the actual PNP switch itself does not get aligned or adjusted. It clicks solidly into each gear position as you rotate the shaft. When everyone is referring to "aligning the PNP switch" what they actually mean is that the PNP is in the same position as the gear shifter in the car. In other words, if your PNP is set in the "Reverse" postion your car's gear shift should also be in "Reverse", then they are both "aligned". Grab the shaft with pliers and rotate it all way to the right. That's "Park". One click left is "Reverse" another click left is "Neutral" and so on. (I was reading more into it and looking for a fine-tuning adjustment on the actual switch itself).

2) S2 Solenoid replacement: This was the most difficult and time-consuming job I have ever had to do on my Volvo, mainly because it was so hard to get to certain bolts and everything was in the way!! I ended up removing a lot more stuff like the bottom radiator hose (had to drain antifreeze) and the driver's side wheel because I like to have room to work. The S2 Solenoid tested bad (about 160 ohms compared to 15 ohms for the new one). Fortunately S1 tested the same as the new one so it stayed.

There are nine #40 torx head screws that secures this black cover to the front of the transmission which houses the solenoids. Most screws are not too bad to get to, but there are two challenging ones. The first challenging one has to be accessed through the driver's side wheel well (which is why I took that wheel off--also had to fold back the plastic wheel well and clamp it). You have to jack up the tranny a couple inches to clear the subframe to be able to get to it. But by far, the most difficult and time-consuming part of the job was getting that last stubborn screw out

. It is extremely difficult to locate and there is almost no way to reach it. The solenoid cover mounts very close to the engine block (making it impossible to use standard 3/8 torx bits sockets) and this difficult bolt is tucked in deeply between there hiding in the shadows. The subframe (or crossmembers) are right in the way too. In fact everything's in the way!

I finally came up with a tool that worked. In order to reach into the tight space I ended up using a quarter inch ratchet with a quarter inch socket. Inserted into the socket was a 4 inch long magnetic bit holder with a #40 torx bit inserted into the magnetic tip. But after numerous failing attempts I had to finally resort to lowering the subframe. Otherwise I couldn't get my ratchet assembly to it. I wedged a 2 X 4 between the subframe and the body (to keep them from reconnecting when jacking up the transmission) and raised the tranny up a couple inches to where the screw was finally accessible to my tool.

But after finally removing that last screw, I still couldn't get the cover off because it wouldn't clear the subframe so I had to jack the tranny up even higher. Then the bottom radiator hose was right in the way so it was removed. Also that filter assembly that mounts down low under the battery tray was in the way and had to be removed also. That's what I mean about so much stuff being in the way. I was getting so frustrated I forgot to have my oil pan centered under the cover and lot of fluid poured out on the driveway. Quickly I got my new power washer out and sprayed off the driveway (to avoid environmental penalties) but I'm not sure how much tranny fluid I lost. It was reddish brown.

Putting everything back together was much faster than disassembly. This weekend I will do the "modified drain" plan that MIJ posted and do my best to make sure I've got 8 quarts in before driving.

Mike850 · Post by **Mike850** » 11 Aug 2008, 10:08

SUCCESS!!

Got everything back together and the car runs like a charm!! The transmission shifts smoothly and no apparant damage was done. It pays to be optimistic and not listen to the negative advice

.

Key points:
First of all, have faith in your diagnostic codes! That's what they are there for. Despite the fact that when I pulled codes in the A1 socket the only code I was getting was 2-2-2 (S1 solenoid) I proceeded to ignore this and change the PNP neutral safety switch instead hoping that would solve the problem. Turned out that wasn't the problem. Most of us automatically assume that when we see the flashing "up arrow" on the dash and the car is stuck in limp mode it must be the PNP switch. Even the good write up in Bay 13 with instructions on how to replace the switch says if you have those symptoms it's probably the PNP switch. But a bad solenoid also causes the arrow to flash. A bad S1 solenoid will prevent the car from engaging into low gear thus taking off in 3rd gear ("limp mode").

If you're car gets stuck in limp mode and you still have to drive it some, don't throw in the towel and just assume you're tranny will have permanent damage. I wasn't able to immediately borrow a vehicle. So for the week I drove the car in that condition I used some common sense. I Drove very easy and never gave it a lot of gas when taking off from a stopped postion. When parking, I looked for a hill or slope to back into so gravity would assist me in taking off. Also, I payed close attention to stop lights and adjusted my speed so that I would meet them when green and not have to stop. And...I even rolled through a lot of stop signs! As long as you are going at highway speed it drives fine. You just don't want to do much if any, stop-and-go driving. That's what really puts the strain on the tranny. But if you are gentle on it, it can survive for a short while until serviced--mine did!

Replacing the tiny solenoid in the transmission is easy once you get the cover off. The hard part is gaining access to remove a couple of the cover screws and what is in the way that has to be removed to get to it.

Transmission fluid: I believe running clean transmission fluid is extremely important. Although mine wasn't too bad (dark reddish brown with a slight burnt smell) I would suspect the transmission got too hot and that's what fried the solenoid. I performed the "modified drain and refill" method until the fluid was cherry red. I used regular Castrol Multi-vehicle automatic transmission fluid instead of synthetic, because I wanted to first make sure the transmission wasn't damaged before spending the money on expensive fluid. But since it appears to be fine, I plan on draining and replacing with good quality fully synthetic fluid in a couple weekends from now. The draining and replacing method is very easy to do and does not take long at all. My wife helped me and it was a breeze.

If anyone needs to know the finer points of removing the front transmission cover to replace any of the solenoids I will be glad to post more detailed instructions--even some pictures!

Post by **Ozark Lee** » 11 Aug 2008, 10:31

If anyone needs to know the finer points of removing the front transmission cover to replace any of the solenoids I will be glad to post more detailed instructions--even some pictures!

Go for it!

...Lee

Post by **MadeInJapan** » 11 Aug 2008, 15:41

Thanks for the update...a lot of people with that solenoid issue are told to replace the transmission. This is certainly refreshing...and done by the owner himself! Yes, like Lee, I too would like to see the write-up. Did you take pictures? We'll pin it!
MIJ