2001 2002 AW55 transmission, history, stop/start software Topic is solved

Post by **matthew1** » 19 May 2016, 10:25

Since there's been a rash of questions on 2001 Volvos with this transmission (AW55-50SN for FWD cars and AW55-50 for AWD cars), here's a sticky topic we can use to share notes and experiences. A highly concentrated AW55-50 info topic. After this topic grows, I'll unsticky it and roll it into Links to Major Repairs V70 & XC-70 (2001-07), S60 (2001-09) supersticky topic, where it will continue to be open to posts.

Here's a table with all recent Volvos and their transmissions. Check if your Volvo has this transmission using it if you don't know.

Here's a page with links to topics concerning Volvo's terrible "Stop-Neutral Transmission" software feature that helped damage and degrade countless 2001 and 2002 Volvo transmissions.

Here is a thread talking about the upside of these transmissions

viewtopic.php?f=9&t=84857

Please post to this thread if you've got relevant AW55-50 information, either first-hand info, or a link here on MVS or offsite.

Thanks!

01_Nautic_V70 · Post by **01_Nautic_V70** » 19 May 2016, 10:46

Thank you. Sorry to be cluttering things up lately.

Post by **matthew1** » 19 May 2016, 11:43

Oh I wasn't pointing fingers, Nautic

. This is just good practice to organize info where there is a bunch of interest/posting on one specific thing.

01_Nautic_V70 · Post by **01_Nautic_V70** » 19 May 2016, 12:24

In this vein, I have a transmission pressure gauge set coming in tomorrow. If my self-performed valvebody clean and rebuild doesn't correct my issue, I'll start looking for signs of either clutch pack and band failure or failure of the ATF pump itself. Does anyone have a table of factory spec pressure tap values (on rear cover) for the various taps? I can do a quick check by disconnecting the cooler, but what really is enough pressure and what is not.

I do suspect there's a pump issue as I noted an increased "whine" from the transmission before it gave out. Almost like a failing power steering pump noise. I'm thinking the noise similarity indicates a failing hydraulic pump. A failed hydraulic pump in an automatic would mean basically nothing works.

Post by **abscate** » 08 Jun 2016, 09:15

Attempt to put this into perspective. From the table the AW55-50 family was used in a lot of P2 s from 2000 on

Is the issue with 2001 and 2002 the start/stop software wrecks these transmissions, but 2003-on they are basically sound as that software was removed?

smileyboy · Post by **smileyboy** » 26 Jul 2016, 17:55

Will a 2003 fit in a 2001 or a 2005 fit in a 2001? Is it plug and play? I mistakenly posted and didn't see this thread.

01_Nautic_V70 · Post by **01_Nautic_V70** » 28 Jul 2016, 14:01

Smileyboy, no. A 2001-2002 are interchangeable only among those years. Then 2003-2004, then 2005-after. So, there are three different "phases" of AW55's in these cars.

Post by **shiloh51933** » 27 Nov 2016, 09:08

abscate wrote:Attempt to put this into perspective. From the table the AW55-50 family was used in a lot of P2 s from 2000 on

Is the issue with 2001 and 2002 the start/stop software wrecks these transmissions, but 2003-on they are basically sound as that software was removed?

I have 2004 XC70 and a 2000 V70XC so this question isn't for me specifically but for this forum. Since the start/stop software wrecks the transmission on the 2001-2002, did Volvo ever make any software updates to correct the issues caused by the start/stop software?

Post by **matthew1** » 27 Nov 2016, 09:45

"Stop-Neutral" software update, Volvo part# 30646691

http://www.volvopartsinternational.com/ ... 646691.htm

A couple topics here on it: https://www.matthewsvolvosite.com/forums ... 8&start=10 and https://www.matthewsvolvosite.com/forums ... hp?t=32636

Post by **precopster** » 08 Dec 2016, 03:03

The SLS, SLU and SLT solenoids behind the valve body cover were a major headache with the bushing material becoming magnetic and attracting metallic sludge that should have ended up nestling in the low mounted filter. Cleaning and re-clearancing these bushings gives some temporary relief but must be done early in the transmission's life before damage is done. Replacement of the valve body is a better more long term fix.