Key socket not working








Inserting the fob in the EIS (Electronic Ignition System) starts a process of several checks within the car's systems to determine readiness to start. In my C320, the Transmission Control Module (TCM) was intermittently working correctly. When it failed its check, the car would not start. When it did start, the tranny went into limp mode, meaning a 7-mile drive to the mechanic in 1st gear. I can't say for sure that this is your problem, because the TCM is just one of many system checks performed. But it was a maddening series of trips to the Indy mechanic at 15 mph.
Once the TCM was replaced, there were other check problems (including parasitic drains) to run down, then the car started performing normally, seemingly on its own. The EIS has NOT been replaced. And 16 months later, the car starts normally every time.
Good luck with this... I can't wish this stupid scenario on anyone...
Last edited by DFWdude; May 23, 2021 at 08:36 AM.
Inserting the fob in the EIS (Electronic Ignition System) starts a process of several checks within the car's systems to determine readiness to start. In my C320, the Transmission Control Module (TCM) was intermittently working correctly. When it failed its check, the car would not start. I can't say for sure that this is your problem, because the TCM is just one of many system checks performed. But it was a maddening series of trips to the Indy mechanic.
Once the TCM was replaced, there were other check problems (parasitic drains) to run down, then the car started performing normally, seemingly on its own. The EIS has NOT been replaced. And 16 months later, the car starts normally every time.
Good luck with this... I can't wish this stupid scenario on anyone.

The steering wheel lock, ESL, is a semi-common failure and it will prevent starting the car. This is what your mechanic is referring to. You can “hack” them and replace the two-cent motor inside without re-programing. Sometimes the chip inside gets burnt due to the dead motor and requires total replacement.


