Ignition Voltage Transformer DIY help.
Thread Starter
Newbie
Joined: Jul 2006
Posts: 9
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Ignition Voltage Transformer DIY help.
Hi, everyone. I'm about to swap the Ignition Voltage Transformer on my dad's 2006 S65 AMG. Basically, this is the little rectangular metal box in the middle of the engine bay.
It seems very straightforward. BUT-- does anyone know if I need to have the unit programmed at the dealership? Or is it just plug and pray... I mean play.
Any other advice would be appreciated!!!
PS-- This is to hopefully fix an intermittent driverside misfire/sluggishness that has been hard to nail down.
It seems very straightforward. BUT-- does anyone know if I need to have the unit programmed at the dealership? Or is it just plug and pray... I mean play.
Any other advice would be appreciated!!!
PS-- This is to hopefully fix an intermittent driverside misfire/sluggishness that has been hard to nail down.
Newbie
Joined: Apr 2010
Posts: 6
Likes: 0
From: Oxford, England
2005 Mercedes CL65 AMG & 1997 E320 wagon
Ignition box swop
Hi, I changed my CL65's coilpacks because of missfires and still had issues. I then fitted a replacement ignition transformer and it cured the problem. The box was a direct swop and didn't need any reprogramming.
Good luck!
Good luck!
Member
Joined: Oct 2008
Posts: 179
Likes: 2
From: Chicago, Naperville area
2005 Mercedes S600, 2004 Mercedes E500 4-Matic, 2002 Mercedes C32 AMG, 2001 Trans-Am WS-6
Even after I replaced both coils and all plugs I still had a random #2 & #7 misfire at startup when warm or if I took her over 4500rpm. I was about to replace the transformer, but on a whim I replaced all the air pressure/temp sensors (one on both air boxes and one above the manifold by the intercooler). Also the downstream air intake sensor in the manifold (ironically I had to remove the voltage transformer to get to it). I also replaced the crank Position sensor (since it misfired when hot at startup) and the coolant temp sensor just for good measure. It cured the misfire problem and is running so much smoother overall!\
I don't know which part it was specifically that cured it, or if it was a combination of all, but I figured the ~$125 I spent on all of those beat the $$$ for the transformer (I don't think they typically go bad).
I think the transformer is Plug and play by the way...but be sure it's firmly grounded (metal to metal) on the bracket with the screws (don't try to use spacers to lift it off the hot engine).
MBWorld Fanatic!
Joined: Oct 2009
Posts: 1,924
Likes: 38
cl600
i had the misfire codes, also engine wouldn't start and made a weird noise when trying to start. had it towed. tech checked coils, both good and finally found a short in the ignition transformer. changed it out and all is good. i think it's a pretty common problem.
Member
Joined: May 2008
Posts: 108
Likes: 0
From: Denmark
SL65 AMG, X5-4.8i M-Sport, 530D, 528i
I had the same issues with misfires. Engine then cold ran ok, but when warm multiple misfires on left cyl. bank. MB changed left coilpack, but problem was first solved when power supply (Ignition Voltage Transformer) was changed.
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Newbie
Joined: Sep 2004
Posts: 12
Likes: 0
From: NW Phoenix, AZ
2004 Silver SL600 & 1998 SLK230 White
misfires on 7 and 9
Hey, before you spend even more $$$ on that transfomer...I had a similar misfire (search the forum for my threads).
Even after I replaced both coils and all plugs I still had a random #2 & #7 misfire at startup when warm or if I took her over 4500rpm. I was about to replace the transformer, but on a whim I replaced all the air pressure/temp sensors (one on both air boxes and one above the manifold by the intercooler). Also the downstream air intake sensor in the manifold (ironically I had to remove the voltage transformer to get to it). I also replaced the crank Position sensor (since it misfired when hot at startup) and the coolant temp sensor just for good measure. It cured the misfire problem and is running so much smoother overall!\
I don't know which part it was specifically that cured it, or if it was a combination of all, but I figured the ~$125 I spent on all of those beat the $$$ for the transformer (I don't think they typically go bad).
I think the transformer is Plug and play by the way...but be sure it's firmly grounded (metal to metal) on the bracket with the screws (don't try to use spacers to lift it off the hot engine).
Even after I replaced both coils and all plugs I still had a random #2 & #7 misfire at startup when warm or if I took her over 4500rpm. I was about to replace the transformer, but on a whim I replaced all the air pressure/temp sensors (one on both air boxes and one above the manifold by the intercooler). Also the downstream air intake sensor in the manifold (ironically I had to remove the voltage transformer to get to it). I also replaced the crank Position sensor (since it misfired when hot at startup) and the coolant temp sensor just for good measure. It cured the misfire problem and is running so much smoother overall!\
I don't know which part it was specifically that cured it, or if it was a combination of all, but I figured the ~$125 I spent on all of those beat the $$$ for the transformer (I don't think they typically go bad).
I think the transformer is Plug and play by the way...but be sure it's firmly grounded (metal to metal) on the bracket with the screws (don't try to use spacers to lift it off the hot engine).
Last edited by turboharley; Sep 28, 2012 at 12:06 AM.
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Super Member
Joined: May 2015
Posts: 554
Likes: 37
2004 S600
Typically you'll have one cylinder bank, or possibly both lose all spark. Can be caused by a number of things though. Not many people good at actually diagnosing the cause of ignition system problems on these cars, everyone just guesses at replacing parts. It's particularly difficult because of the way Mercedes has it set up...if the transformer senses too high of current going to a coil pack it shuts down that half of its power output until the ignition is cycled. Which is pretty much exactly what would happen if that half of it was bad. To make it even worse, there are also lots of other reasons the engine computer would/could disable an entire bank of cylinders. So it makes it super difficult to determine if it's the coil's fault, or a breakdown in the plug/coil boot, or the ignition transformer, or another unrelated problem.
