Hi,

Long time reader, first time posting. I have scoured the site but not been able to find any info relating to this issue especially in relation to W209's.

A few months back my car died (lost power, steering went heavy) and I had to pull to the side of the road. I was eventually able to get it started and drove it to the nearest shop. The mechanic there was unable to diagnose the issue so I had the car towed back home. The car would start and sometimes would stay running for several minutes, sometimes for just a few seconds before turning off. When it did turn off, the radiator fan would go off like a turbine at a very high speed. Once it died, turning the key to power would set off the radiator fan and the car would not attempt to crank, let alone start. However, if I left it alone for several hours and came back to it, it would often start up and stay running; again, maybe for a few minutes or just a few seconds until it died again. This became a cycle. I checked all fuses and relays and found no issues. What I failed to mention, was that I had insured the car after about a year after having it garage kept on a trickle charger. I tested the battery and the alternator under load and found no issues. After much online searching and speaking to some friends, I was told to unplug the ABS/ESP module under the hood. After disconnecting this module, I tried to see if the issue persisted, which it did. I now had a new problem on hand. The shifter was stuck in Park and I have a BAS ESP malfunction notice on my speedometer with an "ABS" light on as well. I reconnected the module and looked online to see if I could find out how to reset these error codes. I tried turning the wheel from one side to the other which seemed to solve this issue for others, but it didn't work for me. I then thought, as unlikely as it was, that maybe it was a brake switch issue seeing as others identified this to be the cause. What I learned from looking through the threads was this model does not have a brake switch and that it is built in to the ESP module. I cannot find much on how to reset these error codes and I do not believe there to be an issue with any of these components because they were only triggered after unplugging the ABS module.

Back to the original issue of the car starting but eventually killing itself... I started with some basic things: so, I changed the coolant temperature sensor and I saw that my belt was fraying and my idler pulley was broken so I replaced those two as well. After doing the temperature sensor, I had the car started for 45 minutes before it died and replicated the original issue. After changing the belt and idler pulley, I had it started for 1.5 hours today. I drove it around the block multiple times successfully (I had to use the override switch beside the gear shifter to get out of Park). Now, I don't believe the belt and pulley would have any bearing (pun intended) on the original issue. So, am I prematurely excited and is it a matter of time the problem replicates itself?! Also, how do I get rid of the problem of the stuck shifter which doesn't appear to have anything to do with the original problem?!

I am desperate for some help or pointers of where and how to start.