1999 Volvo V70 Transmission Issues

kenknowles · Post by **kenknowles** » 12 Apr 2011, 13:15

I have a 1999 Volvo V70 with AW50-42 Transmission. I started getting flashing up arrow and CEL code P0743 (SL Solenoid Electrical Fault). I replaced SL Solenoid and flushed tranny with DEX III. I Have no CEL any more, but trans shifts very poorly, It goes from 1st to 4th very quickly, and does not down shift from 4th to 1st until almost stopped. I have tried replacing the other 2 solenoids S1 and S2 with no change to symptoms.

Solenoid S1 was green, S2 Black and SL Grey, I was told S1 and S2 are green and SL is Grey?

Is there anything I missed? Does the TCM need to be reset somehow? Any Help or suggestions would be appreciated

kenknowles · Post by **kenknowles** » 14 Apr 2011, 19:31

Any ideas?

msafire · Post by **msafire** » 01 Oct 2011, 08:58

I read that there is a software upgrade which may improve transmission preformance. Apparently the software on this Volvo was designed intentionally to kick the tranny into neuetral when idling which in theory was a great idea to improve mileage, but in practical reality didn't work well and resulted in the transmission not shifting properly. Just info from web so can't vouch for accuracy but as the owner of a crappy 99 V70 Transmission I am hoping to get fuctional I read all I can. Apparently the Volvo dealers can provide this upgrade of software which might make a difference.

Also be sure the right transmission fluid is used. Apparently this had a particular synthetic and problems if wrong kind is used. Read that unless a shop works on Volvo's regularly they may use the wrong fluid.

Can you tell me if the solenoid parts are all the same? I got the indicator light of Bad solenoid so ordered one solenoid to replace from PartsGeek.com, and am wondering if I should order more than one before I send the part and transmission to the transmission repair guy to take it apart and clean it out and swap out what I can replace.

msafire · Post by **msafire** » 24 Oct 2011, 08:19

Figured out the solenoid S1 and S2 are the same. Thanks. Let us know how your tranny is doing. My car is getting the solenoid upgrades and flush so will see if that works for me as similar problem with low power when shifting gears ( mine is from going to lower to higher in stop and go traffic but fine on highway once cruising.)

Post by **JRL** » 24 Oct 2011, 08:59

Flush it, get the latest software and it should be better.
It may never get perfect, some just shift harder than others expecially since the valvebody's been apart.
Again, it always helps to post your mileage...

Post by **jimmy57** » 24 Oct 2011, 10:51

The AW50-42 is not the trans with the neutral feature when stopped. There MIGHT be a software upgrade for your transmission but the AW 50-42 99 and 2000 models had only 1, if any, of those upgrade softwares ever and your car may have already had that upgrade when it was a new car. AW 50-42 has a great track record but they do wear out. One of the more common issues with high milage is the end cover which has support for input clutch drum and a planetary gearset, wears and cause shift issues and harsh gear engagement when stopped.
SL is for the locking torque converter function. SL failing either causes TC to stay locked and kill engine when you brake car to a stop and usually no code for this. OR the SL solenoid will have wiring fault or internal short or open and the TC lock will not occur which is more or less invisible as it is a "shift" that happens at 54-56 MPH after it is in 4th gear.

kenknowles · Post by **kenknowles** » 24 Nov 2011, 19:20

Final solution, was the S2 soleniod which was new, was bad. Returned and put new one in and all is fine. Thanks for all your input!

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Danfrom71 · Post by **Danfrom71** » 22 Nov 2013, 14:55

Hi..Does anyone have any info about the AW 42 transmission for a 1999 V70 2.5ltr volvo it changes like it has a 5 speed auto but this model says it has a 4 speed auto ,my vin details are YV1LW55B6X2612160 if thats helpful..thx

Post by **JRL** » 22 Nov 2013, 15:46

That VIN is incorrect, I'll tell you right now it should not have a X in it unless it's a AWD. If so then the engine number should be a 56 not a 55
You may have a 2000 as it's a non turbo they DO have a 5 speed