'94 E 320

[Mino Erhan]

Help Please,

I posted a topic last week on a cold start event here is more info please help.
Thank you!

Car:
1994 E-320 build in february. Do not know whehter wiring harness has been changed or not. I am trying to get the history from the dealer. 67,000 miles, one owner, only a few cat scratches on the car, otherwise flawless from the exterior. Bought it last week.

Problem:
It was 44F car started very reluctently after 4 tries. Got colder the next day, 29F started just fine. The next day 43F again, did not start at first but took 4 tries again, started but set an MIL light.
I now noticed that the car does also not shift into 3rd, but only after it reaches 3000rpm and a certain operating temp. After the car is warmed up its starts and shifts normal.

Observations:
I was cleaning the passenger side carpet when I noticed the following:
Below the insulated carpet there is a small connector (NOT the heater or signal wires for the oxygen sensor) there is some wiring work done. Added wires (2) and a fuse. One goes to the footboard and the other goes to below the right side tunnel towards the console. Is this an update? Looks somewhat professional. I inpsected the wires in the engine compartment, they are hard, but not brittle, and no ends are showing. The engine had been washed when I bought the car.
I have been looking for the diagnostic socket, (awaiting for the manuals) , to see whether I can get the codes out, havent found the diagnostic socket yet.

Question:
I do not have the code yet. Does the transmission potentially have anything to do with the coolant temp sensor? Does the O2 sensor have anything to do with the cold start and the transmission shifting. I thought that mabe they delayed the upshift so the sensor warms up quicker, once its there, things are ok. I dont know.
How do I get the code from this car, all I see is a covered connector (3"x1.5") with a button and what looks like a LED beside it. This connector is on the pass side behind the second firewall. Is this the press and hold for 3-5 secs, button? I have been loking thru alot of posts on the board but havent found anything pertaining to a 94 E320 as far as diagosis. Please help me on these questions as I always appreciate your input.

Thank you again