03 c70 transmission issues
 

Hi guys, I posted this in the wrong section: https://www.volvoforums.org.uk/showthread.php?t=277037

Can anyone have a look at let me know. Thanks.

If you click on the little 'hazard triangle' ("Report Post") in the bottom left corner of the original post, you could ask the mods (nicely) if they would move it for you!

Best thing I'd suggest is to get it connected to a VIDA unit.
If it's the input or output sensor it should let you know in live data to confirm it.
If a sensor does cure it an oil change as well is a good investment to prolong the transmission life

That's a good idea. I guess I'd have to drive it with the machine connected.

Is there a cheap Chinese one available on eBay that does logging? Or would you have to drive with someone sitting in the passenger seat watching the output?

Would something like this be suitable?

https://www.ebay.co.uk/itm/Latest-ve...n/222739378353

Bought the VIDA. I did get a free code reader with the car which I could use to reset the lights and I noticed I was getting codes from it so had a look at translating. Turns out the low-tech free of charge code reader was giving enough information and I needn't have bought the VIDA gear. I've still not got it loaded as the DVD supplied with the kit contained corrupted files which made it difficult to install. I've downloaded the files using a torrent (first time I've tried torrents!) so hopefully I'll get it installed to a laptop.

So to the point... the code reader was showing stuck solenoid no. 3.

As it only sticks after a few minutes of driving I'm going to try a transmission oil change as a first step. Give that a few weeks and see if the situation improves. If not then from reviewing various YouTubes I can see it is possible to get to the solenoids without taking out the box... which is good news.

The transmission oil change went very smoothly. No major spillages. The old oil was dark and smelly. The transmission is about a million times smoother following the change.

It does still have the problem with the solenoid sticking. It doesn't happen until the car has fully warmed up. Also, if you're not driving faster than 30~ish MPH it does not try to change up and the lights stay off and it drives smoothly.

I am hoping that if I leave it for a few weeks it might cure itself. i.e. with the new oil in there it might clean the solenoid and make it work better. While the box is cold the solenoid works ok so it will be cycling bathed in fresh fluid and there's an outside chance whatever sticky crap is on it will wash off. It drives pretty well so will be no problem to leave it.

I had the same problem with mine.. I took the solenoids out and disassembled them.. cleaned them and ran a drill bit though them to top them jamming when warm.. they were full of dirt and also the blue sleeve material had come apart jamming the rods inside. few ours work and its 100000% better. Used to not go into 3rd .. would flare..revs going sky high and then jumping into gear with a bang. If you still have problems id try this method... ;-)

Hopefully I'm not posting too soon!

But it seems to have fixed itself.

As mentioned earlier, it has been very good after the fluid change.

We've been driving it around for a while. If you reset the fault with the cheap code reader it will clear the code. Drives ok when cold. Drives ok below 30mph. Drives ok if you floor it. Only time it was having a problem was when driving normally and going over 30mph. Then the solenoid would stick and the light would come on and it would be stuck in 3rd gear.

However...

Someone accidently left the side-lights on overnight and that flattened the battery. I jump-started it and went for a drive. The battery is fairly new so hasn't been affected by the incident, it starts fine now after a 1/2 hour drive to recharge the battery.

Flattening the battery seems to have caused a full reset of the systems as the car has been driving faultlessly for about 40 miles now. It's never been that good before so I tentatively suggest it may have fixed itself. Presumably the reset from disconnecting the battery (effectively) has caused an adaption cycle to begin and my first drive after the jump-start has caused it to adapt well to the current state as it should.

So fingers crossed... but it looks like it's fixed! Just a fluid change and some patience. I needn't have wasted money buying a VIDA system!

I'd say the moral of the story here is that people should change automatic transmission fluid more regularly. Certainly ignore the 'lifetime fill' advice from manufacturers. It doesn't make sense and it's been proven time and again in the aftermarket that overall you are better off with fresh oil in the transmission.