1998 V70 2.5 Non Turbo Auto, Transmission ECU

JohnnysTubeAmps · Post by **JohnnysTubeAmps** » 23 Nov 2010, 15:38

Dear Guys and Girls,

Firstly to say what a great site, and thank you for all the valuable assistance so far...

Can any of you direct me to the location of the Transmission Control Unit for my car? My car is European (based in the UK) I have already replaced the shift solenoids in the Tranny and the PNP switch (position seems good, using the reversing lights method), but am still having some issues (dreaded "yellow arrow" and check engine lamp).

Ideally, would like to find a way of checking the sensor/solenoid connections back at the TCU, if I can locate it. I know on an 850 it was located in the box behind the washer bottle (3 modules in total). However, the box in my car only contains 2 modules. Would either of these be the TCU? Or is it located elsewhere? I would also like to find a pin-out or connection diagram for the module.

I'm on the verge of buying an OBDII reader so I can better understand the problems... do you think this is worthwhile?

Any assistance you can offer would be greatly appreciated

Post by **MadeInJapan** » 23 Nov 2010, 15:42

Yes, it is in the box- the one marked Aisin Warner or it might just be marked AW...not the one that says Bosch on it (that's your engine ECU). To be honest, I'm not sure if an OBDII reader will read off transmission codes- in fact, I'm pretty sure it won't. In regards to wiring, I'm lost on that. Hopefully someone else who knows more can help in that regard.

JohnnysTubeAmps · Post by **JohnnysTubeAmps** » 24 Nov 2010, 06:22

Thanks MIJ,

Will post any useful info I come across...

JTA

Post by **thecheat** » 24 Nov 2010, 07:30

OBDII reader won't read transmission codes. You can only use VOL-FCR to read the transmission computer. I don't know how much information you will get out of it as I have never stored a code in the TCU.

You will need the software (http://www.ilexa.co.uk/content/category/2/2/19) and you can buy a "VAG-COM" serial cable on Ebay for a few bucks (quid, I suppose) and hook it up to a laptop with a serial port. I believe it will only work with a serial port, not a USB to serial converter.

I spent $20 on a reader forever ago... here's a link to one on ebay.co.uk... (http://cgi.ebay.co.uk/Vag-Com-Serial-Ca ... 5640b45657) for cheap. Then you just need to get the software from the first website. Get the demo first before you spend on the full version to ensure your interface works.

Post by **thecheat** » 24 Nov 2010, 07:34

The product (which is a download) is unavailable... maybe they are updating it to a newer version? When you get hold of a cable, PM me...

JohnnysTubeAmps · Post by **JohnnysTubeAmps** » 25 Nov 2010, 00:06

Great info... thanks for that response
JTA

JohnnysTubeAmps · Post by **JohnnysTubeAmps** » 27 Nov 2010, 08:32

Dear Guys,

Thanks for your help so far... I currently have a transmission with a new PNP switch and solenoids, and have managed to clear the fault codes (did this using an ELM 327 USB to OBDII adapter)

However, the seeds of despair are germinating.... transmission appears to work in the forward gears, but not in reverse. When I put it in reverse, I don't even get the slight movement from the car to say a gear has been engaged. Once in reverse, I can rev the engine, but there is no drive. Also noticed that I don't get any diagnostic/fault lamps coming on.

I'm going to try another couple of ATF flushes (still looking a bit dubious). I'm still optimistic that this may sort things out.

My questions are;

1) Do you think my transmission in toast?

2) It's a great car (good condition, great engine), do you think it's worth the work/cost of replacing the transmission?

Thanks again

JTA

Post by **Ozark Lee** » 27 Nov 2010, 10:50

That is a tough decision and I don't know the market in the UK. In the US we can buy good used transmissions all day in the $300 to $400 range. I don't know what the breakers get for them in your neck of the woods and I don't know how the cars are valued on the used market.

If you can replace the transmission yourself it is likely worth it if you can find a good used transmission. While it is out I would move all of the new parts that you put into your old transmission to the replacement. If you need to pay a shop to do the swap you are likely better off just getting a different car since the labor costs alone will likely equal the cars value. It is not a difficult job to replace the transmission but it is very time consuming.

...Lee

JohnnysTubeAmps · Post by **JohnnysTubeAmps** » 27 Nov 2010, 10:56

Thanks Lee,

I'm gonna have a read up on the tranny replacement... I know there's some available for around the $200-300 range.

Regards, JTA