New to Volvo. 1999 Volvo V70XC P0740 and P1618 show up only when I hit 65+ mph

[WhitewaterSwede]

Hi Everyone!

I just purchased a 1999 V70XC. I love it. This is my first Volvo but I have been lusting after them since the 850 Turbo wagon was on Motor trends cover in the 90's. "150 MPH Wagon !!" if I recall correctly.

I have purchased a 2 owner 1999 V70XC in white with tan interior. It has 180K on the clock and the owners manual has stamps from Annapolis Volvo all the way to 125K service. So I believe it was relatively well maintained.

I have been lurking on the forums for the last few weeks while I contemplated this purchase. It looked good had no codes, matching tires with same tread depth. Fluids were good etc. I thought I had it all covered.

What I am experiencing is no lock up of the torque converter after it is in 4th gear or so I think. I read in the manual that the transmission locks up to save gas and feels like another shift change.

I cleared the codes P0740 P1618 and did a transmission flush. It shifts like butter all the way through 4 gears. When I hit right about 65 MPH cruising it feels like it is shifting ( lock? ). The flashing arrow and CEL come on. They are consistently P0740 ( torque converter lock open) and P1618 (communication code) .

I do 99% of my own work and hope to fix this myself if it is say a S1/S2 solenoid or something less than a transmission replacement.


Any ideas?

I know that a vida/dice would help but I am strapped currently but it is a planned purchase.

Thank you !

PS. New Symptom just showed up. It stayed in third gear when leaving a stop light after my commute of 10 miles. I shut it off at a stop sign and restarted it and it was fine the remaining 2 miles.

[jgjones095]

i too have the same codes showing on my v70xc - occasionally, but its not speed related.
when I get these codes normally the box will stop shifting and get stuck in 3rd.
resetting the codes are the only way to overcome this for me.

what tranny have you got - aw55-50sn?
how does your box shift? smooth with no 'flares'. does it clunk when shifting from P-R-N-D?
Do you have geartronic (semi manual) shifting control?
leaving in 3rd sounds like going into limp mode.

i would say either dirty solenoids or valve body would be causing it - and the 1st place id start.
well after trying an oil change and fitting an external filter.

[WhitewaterSwede]

i too have the same codes showing on my v70xc - occasionally, but its not speed related.
when I get these codes normally the box will stop shifting and get stuck in 3rd.
resetting the codes are the only way to overcome this for me.

what tranny have you got - aw55-50sn?
how does your box shift? smooth with no 'flares'. does it clunk when shifting from P-R-N-D?
Do you have geartronic (semi manual) shifting control?
leaving in 3rd sounds like going into limp mode.

i would say either dirty solenoids or valve body would be causing it - and the 1st place id start.
well after trying an oil change and fitting an external filter.

I do not a have a semi-manual transmission. I have a standard 4 speed automatic AW55-42 I believe. I have PR32L on the shifter.
I do not have any clunks when shifting into any gear while driving or at a stop. I don't believe I have any flares or high rpms when shifting like the trans is slipping. I have not had anymore episodes of limp mode since I did the transmission flush.

I reset the codes with a generic OBD2 scanner from the auto parts store after the transmission flush. They stayed away with 15+ miles of city driving.

I took it on the highway and left it in 3 (to test a theory) and when I hit 65+ mph the Arrow and the CEL popped right back up.

I drove 1.5 hours at 65-70 mph and the transmission shifted just fine with the codes on. It just never dropped below 2500-300 RPM the whole trip. I used cruise control to keep myself out of the boost. The trip computer shows I averaged 20 MPG with about 10-15 miles city and a little over 100 miles on the highway. This seems a bit low.

[JRL]

That's about right
23-26 on the highway only (62-65 mph, level ground)
The minute you get into stop and go, you'll get between 14-16 MPG (or less!!)

[WhitewaterSwede]

That's about right
23-26 on the highway only (62-65 mph, level ground)
The minute you get into stop and go, you'll get between 14-16 MPG (or less!!)

Thank you JRL.

I wasn't sure if the P1618 or the Potential bad, dirty, or whatever is wrong with the S2 solenoid (P0740) was causing lower MPG.

Just trying to put the pieces together to eliminate any information not related to this issue so I don't throw money at it.
I am studying to be an engineer and that is not how you solve problems.

Do you think that another flush with Synthetic ( T-3309 or Royal Purple ATF) would make any difference with the my issue? The limp mode seems to have resolved. If its dirty solenoid it seems that it would improve? I have also read that the Synthetics have certain additives that allow the lock up function of the transmission to function properly that standard DEX III does not.

My vin is in the lower range 256XXXX so it doesn't appear to require synthetic from the factory as I have read in other posts that the 55xxxxx- and up do because of the clutches.

I am a newbie so all I have to go on is what I read on here and the other boards and it is the internet so its hard to verify the poster's expertise.

Thank you again for your help.

[WhitewaterSwede]

Just wanted to update what I did to fix my car. I ended up replacing the transmission with used one with 100K miles $450 for that and $600 for the transmission shop to put it in.

Transmission is doing great and shifts and drives well.

I am getting a clicking sound when I turn the wheel left. It sounds like it is coming from underneath the center console near the shifter. Anyone have any ideas? Did the transmission shop screw something up ?

I am planning to take it down to the local Indy shop to get it looked over so I can continue my march towards stage 0.


Thank you again for all the help!

[JRL]

Probably you need a new front propshaft U joint/bearing (or they did not tighten it or re-grease it).
That's the only bearing you can buy separately on the propshaft
Colorado Driveshaft sells them for about $115, Volvo wants $300 for it!