Sending out the RCM to djtighe, looking for some clarification. Could bad RCM cause P0730 code and limp mode to activate? also saw old CAB overvoltage code from scan.

 

PO730 sounds like either speed sensors or TCU , Maybe a quick fix is to disconnect batt drain power from car (push brake peddle 4 to 5 times)
if code comes back let us know. jim

 

Well, This looks like a good place to start. Previous owner hung some damprid on the kickplate. Looks like it was leaking on to the TCM and AMP. The AMP is toast and the TCM has corosion on several terminals. Going to clean the terminals and disconnect the AMP see where that takes me.

 

@Junkyard Samurai

QUOTE Well, This looks like a good place to start. Previous owner hung some damprid on the kickplate. Looks like it was leaking on to the TCM and AMP. The AMP is toast and the TCM has corosion on several terminals. Going to clean the terminals and disconnect the AMP see where that takes me.[/QUOT

Did you mean "damp rag" ? If so the previous owner may have been trying to capture leaking water caused by clogged drains under the windshield trim. You definitely need to remove the black plastic cowl that sits at the bottom of the windshield ( you need to remove both of the windshield wiper arms ) You will find a set of drains in the middle as well as at both sides of the car. Blow compressed air through those drains and flush them out with water to be certain they drain properly. While you are in there check the siren. If it is still installed it will be in the center of the car under the cowl. Push and hold the red button on your FOB for a few seconds and listen for the siren to sound. If you get no response or a very weak sound then disconnect it and remove it. You can drive the car with no ill effects without the siren.

 

Damp-rid is a moisture absorbing product. You are right on with the diagnosis though.

 

Drains Cleaned
Said bye bye to the siren ( solved some parasitic draw issues )
Amp is unplugged ( solved some MORE parasitic draw issues )
TCM connectors are now corrosion free and juiced up with a bit of dielectric grease.

I can see the gear numbers on the dash indicator now at least until it shifts into 2nd and stays there until I restart the car. ( My spider senses tell me a new Conductor plate is in my immediate future )
Anyone know if im correct in assuming that the Conductor plate for our cars do NOT need reprogramed like some of the other Mercedes transmissions because the TCM is external?

 

i can tell you that dielectric grease is not good on this car. I learned 24 years ago that it will in a week
or two give you a false reading besides you need to send your TCU RCM to DJ (https://www.crossfireforum.org/forum...-no-start.html) we all think we know how to fix a small electoral problem but believe me
he has a test bench set up to test every part of the TCU RCMI too have a elect backgroung and learned very early that all my RCM's
.I had one srt6/8 that would go into limp mode every so offer on, a hard take off and or a hard corner, Nothing to do with no start.
sent my RCM to Dj he found a relay that was opening when it was supposed to stay closed, oh this was on a brand new K40 as we know it RCM. jim

 

Jim, I believe you are showing your age as you say "TCU" as quoted above, but I'm pretty sure you mean RCM. @amx1397

 

Don't jump to conclusions about the conductor plate. (It does not need programming) IF you need a new plate be sure to get one that comes complete with the solenoids and speed sensors already installed. Get a complete unit not just a plate which you have to make the swaps with solenoids.
BEFORE you go that route contact tighed1@hotmail.com You can send your RCM to him in AZ he will rebuild it better than new. After that is installed in your car you can move forward with any other problems which may show up. GOOD RCM IS FIRST AND FOREMOST.

 

LOL me old come on now ,,,thanks zip for catching that, yep getting there just this morning i forgot to eat breakfast oh sh** it is still morning.
corrected ALL those tcu/rcm, three little letters can make your car go backwards LOL jim