All instruments turn on and off
I have a 1999 E300D with 202,000 miles on it. When ignition key is turned to on all instruments and lights flash on and off several times and stop before you can start the car. sometimes the flashing does not stop until you turn the ignition off and on again. The car starts and runs near perfect. The problem does not occur at every start, normally after sitting for several hours. has been going on for several weeks. Checked the battery, which is good. checked all connections in ECM compartment. Finally wife took to MB dealer while I was out of town and they "took apart" and put back together and problem stopped for 2 days. Last night after dinner car would not shift out of 2nd gear. I pulled over turn car off, let sit 1 minute started again, no instrument flashing and car drove fine. I'm suspecting the ECM is going bad, but no way to verify. Could take back to MB dealer, but I'm afraid of the cost and admitting defeat. I always repaired my own car. Suggestions?