1995 850 transmission only has 4th gear,reverse & park

4sdAIR · Post by **4sdAIR** » 12 Apr 2015, 15:14

Hi, Well my trans was showing the shift arrow intermittently for about a year and each time was in limp mode. Finally always in limp mode I looked at the codes 2-2-2. I took the trans valve body off and tested the solenoids. The SL solenoid (lock up) wasn't working so I changed with a new one, put It back together and wha-la the problem still exists. The computer code is still 2-2-2 (Open circuit). Any suggestions as to what the problem might be or where can I find instruction to test the pnp switch before buying one? Is there anyway to test the solenoids without having the take the trans valve body cover off?

Post by **Ozark Lee** » 12 Apr 2015, 16:21

It sounds like a bad PNP switch is throwing it into limp mode. My guess is that the car is actually using 3rd rather than 4th which is the default limp mode.

You can resistance check the solenoids through the connector.

The measurements reference ground:

S1 pin 21 (green/white wire)
S2 pin 22 (brown/white wire)
SL pin 23 (brown/black wire)

STH is between two pins rather than ground pins 24 and 25 (violet and violet/white wires).

You can download the factory manual from this link

https://www.matthewsvolvosite.com/downlo ... vo_850.zip

After you unzip it see the file named auto trans diagnosis.pdf

...Lee

4sdAIR · Post by **4sdAIR** » 12 Apr 2015, 19:52

Real good information. I'll do a resistance check and see what happens. I'll keep you posted. Thanks

4sdAIR · Post by **4sdAIR** » 13 Apr 2015, 19:47

HHHMM is it the connector at the TCM on the passenger side of the engine compartment or is it the connection on the transmission on the drivers side near the pnp switch?

Post by **Ozark Lee** » 13 Apr 2015, 20:18

I think those pinouts reference the big fat one by the PNP switch.

...Lee

4sdAIR · Post by **4sdAIR** » 13 Apr 2015, 21:46

I followed the direction in the AutoTrans pdf that you showed me however I didn't figure out how to get into test mode No 4 from the onboard diagnostic; 2) Turn ignition off. Connect measuring unit to TCM. Connect ohmmeter between measuring unit terminals No. 20 and 28. If ohmmeter
reads about 10-15 ohms, repair poor terminal contact at TCM connector. If ohmmeter does not read about 10-15 ohms, go to next step. (3.1ohm was read) 3) Remove air cleaner housing to access transaxle connector. Disconnect transaxle connector. Connect ohmmeter between transaxle connector terminal No. 22 (Violet wire) and measuring unit terminal No. 28. If ohmmeter reads about zero ohms, go to next step. If ohmmeter does not read about zero ohms, check for open circuit in Violet wire. (3.1ohms was read) 4) Disconnect transaxle connector. Connect ohmmeter between transaxle connector terminal No. 22 (Violet wire) and ground. If ohmmeter reads 10-15 ohms, repair poor terminal contact at TCM connector. If ohmmeter does not read 10-15 ohms, go to next step(read 31.1 ohms). The last step it to remove the solenoid but Im reluctant because of the work involved. Ps there are no codes in the TCM but after driving it was great for the first while then stopped to open the gate at home and boom back into high gear when I put in in drive. No code was registered either. Is there a way to test the PNP switch?

Post by **polskamafia mjl** » 14 Apr 2015, 10:30

I don't know of any test for the PNP but it is easy to clean. Spend the 2 hours cleaning the switch and see if that fixes the problem.

4sdAIR · Post by **4sdAIR** » 14 Apr 2015, 18:18

I was thinking the same because no codes are being stored it must be mechanical in nature because if it is a faulty switch / solenoid a code would be registered. I'm going to try it tonight and I'll keep you posted.

Post by **Ozark Lee** » 14 Apr 2015, 20:07

The diagram on the last page in that .pdf file has the PNP switch and the pinouts / wire colors (it is called the transmission range selector indicator in the diagram) so you could use an Ohmmeter in the various shifter positions to test it.

...Lee

4sdAIR · Post by **4sdAIR** » 14 Apr 2015, 22:07

Well I took the PNP out tonight and it would appear that it's been rebuilt once before. They had a hard time getting the 3-pin connector out of the hold that is bolted to the trans and drilled a hole in the one end and used black silicone to seal it. I carefully split the two halves of the pnp apart and the copper contact look worn as well as the copper contact held by the springs. Anyway I'm not going to rebuilt and purchase another not to say the new one will be without problems but I get a Volvo one I should be good to go. The care has 330000km. I'll keep you posted. Thanks for the suggestions all.