1999 V70XC Transmission woes.

aquamann71 · Post by **aquamann71** » 16 Mar 2014, 09:18

This is my first Volvo and my first post. I purchased my car about 2 months ago. It had a couple of small problems from the get go. The traction control light come on intermittently and the ABS light is on all the time. I am currently waiting for a reconditioned ABS module and from what I read this should resolve the ABS problem. The check engine light is also on and my code tester suggests the upstream O2 sensor is in need of replacement. Preparing to swap it with a new one.
What I Can't seem to figure out is what's been going on with my tranny. It was working OK when i first started to drive it except for sticking in first gear until I left my foot off the gas for a second. Also, it was shifting a bit rough and sometimes wouldn't shift into overdrive. This went on for about a week and now i have no overdrive at all. So I dropped in some Seafoam to clean it and after another few days I drained the tranny and refilled with 4L of fresh fluid. After another week the fluid is quite dark and smelling a bit burnt. Still no overdrive but shifts much smoother. I read in your forum after the fact that this probably wasn't that good of an idea.
I've read a lot of posts since then and people seem to think that there could be a problem with the overdrive solenoid. I haven't tried to replace it yet. I also read about the PNP switch on the tranny that tells it what gear it is in. First I tried shifting the gear shifter up and down to clean the contacts. After that i ended up with no reverse. I removed it, cleaned it and replaced it, still the same. Then i removed one off of my spare car and tried that. Nothing. I tried adjusting the PNP to no avail. Later i figured out that if I put it in park and shift slowly into reverse it slowly creeps into gear. Once it's in reverse it acts just as it should. Still no O.D.
I am about to remove the return line to the transmission and pump out the old fluid and replace it with new. Does anyone think this may resolve some of my issues or am I about to waste more transmission fluid? Would a malfunctioning transmission act in this way or would it just stop working all together? I have a spare transmission but before I swap it out I'd like to try all the other options first.
I've read about a few people with the same problem but they never post if they figured it out in the end. Please help! Thanks to whoever can give me some assistance.

Post by **Ozark Lee** » 16 Mar 2014, 17:13

There is no "overdrive" solenoid but you may be describing the torque converter lockup. It should kick in at around 45 MPH. The solenoid will also not engage if the transmission computer detects your foot on the brake. A bad brake switch can cause it to no function as well.

Have you read the codes? A bad shift solenoid should post an error code.

The black transmission fluid is troubling. My daughter was griping about rough shifts and her fluid looked like filthy engine oil. I changed it and 50 miles later it was black again and the transmission quit altogether. That was in early winter and I have not yet messed with the car, I just gave her the spare car to drive. If winter ever ends I'll dig into it deeper but I think it may be terminal.

...Lee

aquamann71 · Post by **aquamann71** » 25 Mar 2014, 15:05

So here's an update. I figured that I'd drive it with the old transmission, black fluid and all until it finally kicked the bucket. Then i would swap it out with my spare. After driving it for another week, the reverse gear started returning with about a 7 second delay. After returning home after a lengthy drive last night the reverse gear now engages instantly. I tried it again today and it works like it did before. Do u suppose that after putting in transmission additive, some sludge either plugged up a port or a valve and now as extra time has passed, the sludge has finally cleared out again? I still have no overdrive gear but I'm thinking that after i change my ABS module, that might return as well. The only code my car is showing is 1551. I have read that this is related to the speed sensor, which is controlled by the ABS module. Any suggestions/ advice from out there in Volvo land?

Post by **Matty Moo** » 25 Mar 2014, 16:13

You need to do a series of drain and fills. By doing only one you're only getting less than 1/3 of the fluid out.

Did you order that ABS module through me? If so you ordered the wrong one.

aquamann71 · Post by **aquamann71** » 25 Mar 2014, 17:20

Yes, i did get it from you. How am I to get the wrong one?

Post by **Matty Moo** » 25 Mar 2014, 17:50

You ordered a unit for a car with stc traction control, your car is an AWD so it has Tracs. It will work just fine either way.

aquamann71 · Post by **aquamann71** » 25 Mar 2014, 19:52

So, should i send it directly back to you when i get it? I really would like to have the correct module.

Post by **Matty Moo** » 25 Mar 2014, 20:57

I wouldn't. They both serve the same purpose but stc is more effective as far as traction control goes.

aquamann71 · Post by **aquamann71** » 26 Mar 2014, 11:56

So how are the two modules different. If I install the module that you sent to me, will it make my car work OK? May it trigger any engine/transmission codes? I don't mind waiting extra time for the correct part. Sorry about the confusion. I was almost sure that I ordered the one for AWD.

Post by **Matty Moo** » 26 Mar 2014, 14:04

TRACS engages just the brakes in a low traction situation, STC will engage the brakes and retard the throttle. They're cross-compatible with each other, realistically STC is the better of the two.

If you want to shell out the postage to get a TRACS unit, that's up to you.