I recently bought a 99 CLK320 with super low miles. less that 13K. The trans now is in limp mode. I have the following codes: P0753, 758, 763, 743, 702, and 715. I have done a resistance check on all solenoids and put power to them. They are good. I've removed the harness from computer to trans and continuity is good on all connectors. I am failing one test and that is the power wire from computer to the trans. I know this is where my problem is but am unable to figure it out. I bought a new trans module from the dealer and that module doesn't have power on pin 38(+) and 30(-). I have checked the conductor plate for any shorts but everything looks good. My problem is that the car stays in 2nd gear and will not shift. The trans was very clean inside and the oil was not bad. I have serviced the trans and I am about to drive this car off a cliff. Any help would be highly appreciated. Thank you...

 

it's in limp home mode alright. was it a 722.6 trans?

on this case you sometimes need to CLEAR OUT THE FAULT CODES. have you done it?

 

When you unplugged the electrical connector, was it wet? The most common problem in my experiance has been the seals allowing ATF fluid to leak into the connector causing goofy codes and limp mode operation.

 

Yes it is a 722.6 trans. I have cleared the code. Still nothing.

 

No the connector at the trans was bone dry. Not a drop of oil inside.

 

you must be kidding Razman.

the pin 38 is the power supply for the valves (actuation is negative in milliamps).

the pin 30 is the ground for the whole control module. without this, it will get ground from somewhere else and... kaputz, it is finish, burned, damage, fkdup.

let's get this straight, you replace the ETC. did you read and transfer the coding? how did you do it and what did you use?

the part number is the same? give me the vin and part number of your original and replacement part.

i will continue......

 

does pin 13 got power? don't tell me it has no pin 13 too. this is the power supply for the speed sensors on the same area. (u got two, actual and slip).

now, make a connection from pin 13 to pin #6 of the VALVE BODY. detach the white wire that goes to pin 38 of ETC first. YOU DO THIS FOR TESTING PURPOSE ONLY.

now supply the ground to valve body. that pin 30 is a ground that goes to the front seats cross members.

delete faults.

does it work now????

THIS PROBLEM IS VERY EASY TO DO. I THINK YOU ARE DOING THE WRONG PROCEDURE.

 

The ground on pin 30 has good continuity to ground. I thought the 38 pin should read 11-14v. Battery voltage. for the solenoids in tranny. I went to dealer with old one. He gave me a different one but said it was a replacment. pin 13 according to my notes is reading 6 volts. But i will recheck it and let you know. Thanks Sleepwalker.