Gearbox valve body and plate interchangability.
Thread Starter
Super Member
Joined: Oct 2023
Posts: 538
Likes: 190
W221 S500
I should have been a bit clearer. I am considering a used TCM/valve body from a 2015 X166 GL550.
According to WIS they are electrically the same with regards to the connection to the car... The 4/5 pin question is moot as the plugs are actually 6 pin but interchangeable as the pinouts remain the same. Verified this with the chassis numbers to both vehicles. I have read elsewhere that VGS2 4 uses different protocols to VGS2/3.
The gearbox isn't changing up from second. Fault codes suggest a TCM failure along with slipping.
Replacing the TCM should resolve the TCM but not any mechanical damage, but it requires the TCM repair to be able to drive it enough to confirm any mechanical issues.
I am reluctant to put a new TCM/valve body into it only to find the box needs rebuilding, so have been looking at 2nd hand.
However my local Merc specialist suggests that he is unable to recode used TCMs. Which means that I would require a new TCM even with a used gearbox.
According to WIS they are electrically the same with regards to the connection to the car... The 4/5 pin question is moot as the plugs are actually 6 pin but interchangeable as the pinouts remain the same. Verified this with the chassis numbers to both vehicles. I have read elsewhere that VGS2 4 uses different protocols to VGS2/3.
The gearbox isn't changing up from second. Fault codes suggest a TCM failure along with slipping.
Replacing the TCM should resolve the TCM but not any mechanical damage, but it requires the TCM repair to be able to drive it enough to confirm any mechanical issues.
I am reluctant to put a new TCM/valve body into it only to find the box needs rebuilding, so have been looking at 2nd hand.
However my local Merc specialist suggests that he is unable to recode used TCMs. Which means that I would require a new TCM even with a used gearbox.
Thread Starter
Super Member
Joined: Oct 2023
Posts: 538
Likes: 190
W221 S500
VGS3 is backwards compatible with VGS2, however I don't believe that VGS4 is.
The TCM, ISM and EIS/Key are pretty much the only theft relevant parts fitted to the W221. An exception might also be the KeylessGo ECM.
Banging the Benz Ninja drum is futile unless you're prepared to share your kit to enable him remote access to my car... as by the time I have forked out for Xentry/DAS etc I may as well have bought a new TCM and Valve body from Mercedes as they're about the same price.
The TCM, ISM and EIS/Key are pretty much the only theft relevant parts fitted to the W221. An exception might also be the KeylessGo ECM.
Banging the Benz Ninja drum is futile unless you're prepared to share your kit to enable him remote access to my car... as by the time I have forked out for Xentry/DAS etc I may as well have bought a new TCM and Valve body from Mercedes as they're about the same price.
Super Member
Joined: Feb 2007
Posts: 601
Likes: 285
From: Republic of Texas
W203 W212 W211 R53MCS
@AL5461 Good luck buying a conductor plate or a valve body from the dealer. They will not sell it to you. You can do it at the dealer which will probably run about $3k for a valve body or you can find an independent shop that has the license to purchase the parts and the equipment to program, code, personalize and activate the new unit.
