My Transmission is not Shifting like it used to?

Well if you are one of the few that are fortunate enough to afford a 2004 Mercedes S500 you might want to listen up. These are some pretty good and reliable vehicles but, like everything else, it can have its issues. More often we are hearing complaints form drivers indicating an issue with the transmission.

The Car won't go over 30 mph, the check engine light is on and the transmission doesn't shift properly.

After taking the car to the shop and having computer diagnostics done with a scan tool, we get the codes P2066, P2071-008, P2203 - No Communication, Replaced Transmission Control Module
and Wiring Harness.

The reason the car won't go over 30 mph is for the protection of the vehicle and is put into "LIMP MODE". This is a result of the transmissions incorrect shifting.

P2066 – Fault is Stored in Component N15/3 (Electronic Transmission Control Module)

P2071-008 – Start Enable of DAS not Sent, Check Fault Messages in Electronic Transmission Control Module

P2203 – Internal Electrical Check of Component Y3/6N (Crankshaft Position Sensor)

We tried to access live data and could not communicate with our scan tool. checked the ETC module wiring harness at the transmission connector and found trans fluid had leaked onto the wiring harness. Followed the wiring harness to the ETC Module and removed the connector. Found the ETC module was full of transmission fluid. 

THE FIX:

We ended up replacing the automatic transmission control module and the wiring harness. We cleared all stored codes. Test Drove and she runs like she should.... no more lights on the dash and shifting properly.