W124: Code 40, Pin 8 - PeachParts Mercedes-Benz Forum

juribe2 · #1 07-30-2007, 11:45 PM

Hi,

I have this thread http://www.peachparts.com/shopforum/showthread.php?t=195616 about my transmission problem.

I decided to open this other one because I just foud this fault code and wish someone could give me some advice about it. I'm taking the car tomorrow to the shop to get the transmission fixed but I'd like to know if there is something special about this code (a cause or consecuence of the problem) and if I should tell something else to the mechanic before they start dismanteling the transmission.

Code 40: ""Transmission overload protection switch - open/short to ground or B+ or open or closed or implausible"

Thanks again guys.

mbdoc · #2 07-31-2007, 08:21 AM

That code is a OUTPUT signal that tells the fuel computer to reduce torque from the engine so not to damage the transmission during the 2nd to 3rd gear shift.

HAS nothing to do with trans operation.

juribe2 · #3 07-31-2007, 09:22 AM

Thank you M.B.Doc

But why did I get that code? Is it because the transmission got bad and the computer is limiting torque to avoit aditional damage? That sounds too smart to me. Or is it normal to get that code even with the transmission working ok? Or is there something else that I need to fix, aditional to the transmission itself?

Thank you.

mbdoc · #4 07-31-2007, 09:36 AM

Possibly a bad switch OR the wiring that attaches to the switch.

juribe2 · #5 09-12-2007, 04:26 PM

Hi,

My E320 722.5 transmission was overhauled some weeks ago and is working perfectly. At that time the code was deleted and didn't come back for some time.

But yesterday, I noticed this faulty code is coming back. What should I look? Where is this switch located? Engine wire harness was replaced about 2 years ago.

Thank you again.