1997 850 GLT Transmission slip w/ flashing arrow

Cox Abele · Post by **Cox Abele** » 15 Jun 2015, 23:03

I'm a noob to this site, but this isn't my first time turning a wrench. I've been doing my homework after buying a 1997 Volvo 850 GLT with a 50-42LE from a co-worker for $240.00. The car is not drivable, so it was sold to me for the price of scrap.

The last owner got the car as a trade for something- who knows what. When he got it, he knew the transmission was having issues. He did a few drain and fills, but the orange arrow light had always been on. The fluid was pretty bad so he tells me. He continued to try to get the car to fix itself while doing a few upgrades to the intake, then lost interest when his fluid exchanges weren't curing a fairly obvious electrical fault.

I step in and take the car off his hands for a pittance. I limp it home after learning about the PNP row. In the 5 miles of driving, the transmission would begin to slip on three different occasions. The orange arrow tanning me with it's wonderful glow the entire way home. Each time it would being to slip, I'd pull off, shut the car off, row the shifter and immediately start on with my blinking orange arrow pointing the way.

I presumed that the PNP switch was toast, so I threw a new one in for $100. I presumed wrong. Once installed and aligned by the reverse light method, I took the car for a test drive, throwing caution to the wind once again as the orange arrow pointed me around the block. Almost immediately the transmission began to slip, however this time, the rowed shifter would not provide any further assistance in getting me home. I coasted, limped and prayed until I hit my driveway when the slip was just too much for the car and it wouldn't move any further.

Today I poked back through the repair manual and started my testing. First was the mode switch which was found good. Next I checked the WOT switch which I found may need replacing, although it's purpose right now is moot since continuity is only necessary at WOT. Without the WOT switch, I just don't have kick down ability. That's the least of the worries right now. I'll address that later. Next I popped open the very familiar 26-pin transmission connector and started ohming out the temp sensor (found to be fair), the S1 and S2 solenoids (also fair), the SL solenoid (zero continuity to ground, bad!!!) and line pressure solenoid (also fair).

So, the torque converter lock up solenoid is toast. Lock up happens only at select speeds, temperatures and RPMs.

The first few moments, the car will drive beautifully, albeit in 3rd only. Converter engagement is solid with little to no slip detected depending on throttle input. It's not until about a minute and a half into driving that the fluid gets to operating temp and the car begins to slip. Fluid level is fine, and it is clean as the previous owner DNF'd it a few times. Rowing the shifter doesn't do much and I've been unable to extract any codes from the ECU. Clearly the SL solenoid is testing faulty, but does the symptoms clearly indicate the solenoid is at fault?

My biggest concern is that I have $240 into the car, $100 into a PNP and another $45 into a new SL solenoid (ordered today). I'll have a ton of time invested (which I don't have much of) to install the solenoid, however beyond seeing the fault, I'm not terribly interested in throwing anything more time or money into a flip car then I'd have to. If a failed lock up solenoid will create slippage once warm, I'll give it a shot, but if the solenoid doesn't seem to be the answer, it may be best to cut my losses and send the car to be crushed.

Do you think replacing the SL solenoid is going to fix my flair up issue?

Cox Abele · Post by **Cox Abele** » 16 Jun 2015, 19:51

Ah, I failed to mention, so far I have not had a CEL come on and haven't been able to pull anything from the ECM regarding transmission issues using my Snap-on Solus. Sadly, I don't have the Euro upgrade, so I'm having to do it all globally, but based on pid graphing the engine seems to be running great!

mika · Post by **mika** » 17 Jun 2015, 14:50

Great spirit. Looks like you are good at troubleshooting. I am interested to hear about the SL solenoid you ordered. Not much to offer besides some encouragement.

Cox Abele · Post by **Cox Abele** » 17 Jun 2015, 20:29

Installed the SL solenoid and my blinking orange light is now gone!!!!! Great!!!

But I have no forward or reverse gears. Of course, I had to add new fluid due to having the pan off. Once it was filled I fired the car up and gave it a shot- nothing.

After testing the car with the new PNP switch, it began to slip just as it had before, thus the further diag time. Now I'm wondering if the constant 3rd gear driving the previous owner was doing didn't absolutely kill this thing or if I've desperately over looked something.

Quickly ran to the store and grabbed two quarts of Lucas, drained the appropriate fluid and added the Lucas- nothing

Every blue moon the trans will engage, but any load against it and it slips off again. Fluid level has been checked countless times, so I'm going to let things marinade and try again tomorrow. On the list is a cold fluid check and running a dedicated ground to the transmission. It's as if the trans won't engage any gears at all.

Cox Abele · Post by **Cox Abele** » 17 Jun 2015, 20:33

Just checked and I have good continuity between the transmission case and the negative post. GRRR!!!!

Edit:

I still have my old PNP switch. I've been sitting in front of my computer staring blankly trying to think of what could be causing this. Obviously internal failure of the transmission is a fair assumption- perhaps I finally completely wore out the frictions. I could have knocked something around inside the transmission while I had the pan off, but I'm fairly confident I didn't. Pulling the pan off again is highly frowned upon without some kind of definite purpose besides inspection. That pan job is a mo-fo.

I aligned the PNP switch with the reverse light technique, but the switch adjustment was pretty much maxed out to get the lights to come on. I scribed the cable bolts, so they should be fairly close. I think this will be my best option and greatest hope that I screwed up the install of the PNP and I'm not getting solenoid engagement at the proper lever position in the valve body. Either that, or the new PNP is not very good. In the park position I can start the car. As I shift the gear lever down to the next position, I get reverse lights. With the gear lever in the N position, the vehicle will not start. As I begin to draw the lever to the drive position, I can start the car, but the engaugement is still much closer to neutral than it is to drive. Mode selection and winter mode are now accessible and I get a solid up arrow with pulling into low gear or selecting winter mode. Neither produce transmission engagement.

Cox Abele · Post by **Cox Abele** » 18 Jun 2015, 19:45

Installed the previous PNP switch which clearly has a bit more range to it. Set it again with the reverse light method and ensured everything was aligned with the transmission. Sadly, this transmission still won't engage.