Solenoid B

[hsingh7000]

Hi guys,

I have 2003 Audi A4 1.8t CVT FWD. It's giving error code P0778 for "Pressure Control Solenoid 'B' Electrical" right after I changed the transmission fluid. The MIL is on and the PRND is flashing and car is not able to accelerate as this code seems to trigger a transmission lock....The current mileage is 140k...I'm planning on opening the transmission cover and was wondering if anyone could point me to the location of the specific solenoid involved.

The TCM has already been repaired and I've already triple checked the transmission fluid level and it's not the problem so thats why I'm having to drain it all out again and pull of the cover to test the solenoids. Just want to avoid having to test all of them if anyone knows which one it is I'd appreciate it.

Thanks in advance.

-Hap

[diagnosticator]

You can use VCDS to test solenoid B, without draining the trans. You can also view the the solenoid status in the trans control unit measuring blocks.

[hsingh7000]

Hey,

Appreciate the info. I'll hold on opening up the tranny then...Do you know if the VCDS is compatible with wireless wifi OBDII Adapter or will I need to go get a USB one?

I have this one...
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thanks again

-Haps

[diagnosticator]

WiFi should be compatible, as a link between the PC and the OBD II port. However a WiFi link is always more problematic than a hard wired connection on USB>OBD II port.

[hsingh7000]

I tried it, it recognized the port but gives error "Interface not found"...I'm assuming VCDS is only compatible with the Hex-Net interface that comes on the dongle/wire that they sell. I will update once I have a compatible interface.

We should do like the farmers here in US and protest that car companies provide all diagnostic equipment with the vehicles we purchase lol

Thanks.

[hsingh7000]

Hey guys,

I'm going to forgo the whole VCDS thing and just go commando on the transmission. I found a picture on line of the CVT valve body and circled in red what I believe to be the posterior end of the solenoids. There are three and if anyone can confirm or point me to whichever is "Solenoid B" I'd appreciate it.

[hsingh7000]

One more Question.

Anyone know the torque specs for the screws for the valve body, solenoids, and TCM? or where I could find out?...couldn't seem to find them on line.