2001 V70 T5 Auto transaxle problems

[01_Nautic_V70]

The valve body has been removed. No readily visible blockages in any ports. No sign of the missing dipstick material. All solenoid resistances seem ok. S1-S5 are 13 +/- 0.5. SLT, SLS and SLU are 5.5-5.6. Is there a way to trigger these while out of the car? I have access to a programmable power supply at work, but would prefer to test these at home.

Alternately, could I put it back in the car and trigger it with VIDA activations for the solenoids? I assume they should all operate freely without binding up.

[01_Nautic_V70]

So I've completely disassembled the valve body. No obvious signs of wear really. A few small bits of varnish looking substance found, but doesn't seem like a smoking gun. I've cleaned it all up and loosely assembled until the new gasket kit arrives.

The front plate's gasket has many cracks in it. Is that normal?

After reassembly, I'll put it back in the car and try to activate solenoids with VIDA to verify operation. Should I also hot oak the SLU, SLT and SLS solenoids to see if they're binding when warm?

And if this doesn't work, it's time for the transmission to come out completely.

[01_Nautic_V70]

I did find something strange this evening. I reinstalled the valve body loosely and used vida to change the state of each S1-S5 solenoid. All clicked, except S4. I swapped the wires for S4 and S5. S4 clicked and S5 did not.

Does anyone have a wiring diagram showing where the purple wire in that loom goes?

[01_Nautic_V70]

In another thread, Mike (precopster) mentioned that the S4 solenoid has no spring return. I guess that could explain why the VIDA-driven activation for that solenoid didn't do anything without having any hydraulic pressure or whatever it is that drives that solenoid to the "OFF" position. Just to double check, I'll bench check the solenoid and then just look for the voltage to change at the S4 solenoid connector when I use the VIDA activation.

[01_Nautic_V70]

S4 solenoid checks out just fine with external power supply. Going to check the supply wiring to it (runs straight from valve body wiring harness to TCM backplane connector) this evening.

[precopster]

Yes ignore the lack of clicking noise on S4 return because the return is activated by line presssure passing through the solenoid. Once line pressure occurs it will click again during activations in Vida.

The cracks in the VB gaskets are hopeful clues because they would affect line pressure. Good luck!!

BTW spoke to the second owner of a 2001 XC70 the other day that has 470K kilometres on original trans!! When I.asked if fluid changes were done he noted regular changes in service records since new at regular intervals. Perhaps this is the world's first 250k mile AW55-50SN!!

[01_Nautic_V70]

250,000 miles? No valvebody or solenoid work done on it at all? If so, that gives me hope that, once this is all sorted out, regular maintenance may keep it on the road for years to come.

[precopster]

Actually it's 290k miles if converted properly. And the valve body hadn't been touched either.

My wife's 2002 XC70 has 313k kilometres or 194 k miles with a 3rd gear band clamp replacement by me and a VB refurbishment by me. Doesn't shift perfectly and occasionally codes P0700 however I connected an ELM327 permanently to the OBDII connector and a quick clear of codes with Torque does the trick. Not ideal of course and far from resellable.

[01_Nautic_V70]

I did locate all of the missing dipstick piece. So that is definitely loose in the transmission now.

[01_Nautic_V70]

Using a voltmeter, I did verify continuity of the wire to the S4 solenoid and saw it go to 12V when commanded. So that all seems ok.

Heated the linear solenoids and did hear them moving easily. Though I did get the dirtiest fluid I've yet encountered out of them after heating.

Just waiting on the new gasket kit to finish up reassembly and give the whole thing a try.