[High School Auto Shop]

Hello,
I work at a high school automotive class and we had a 2017 Smart Car Passion donated to our program. The gentleman that donated it pulled it behind his motorhome and must have had it in the wrong gear and burned up the transmission. We bought a used trans and put it in with the original computer. The car has never started or rolled over since we got it.
After we put the transmission in it still wont start and when the shifter is in park the indicator on the dash says neutral and when you shift it out of park it gives the three lines of death. Also when you turn the key on its says parking lock malfunction.

 

[Bob Ricewasser]

Try doing a transmission re-teach by turning the key to #1 position (KOEO). Slowly move the shifter from Park, Reverse, Neutral, and Drive. Then slowly move the shifter back to Park. Hopefully, you will hear some activity coming from the transmission as it learns what gear it should be in. Also, have to tried to pull any DTC's? That may give you a clue as to what might need attention. The other thing you may need is to hook the car up to a Star Tester and reprogram the transmission. Hopefully, you will have access to a Start Tester. If not, maybe you could get your local Mercedes-Benz dealer to help you diagnose why your 453 won't start. There could also be some factory warranty left on this car and these issues could be covered.

 

[High School Auto Shop]

Try doing a transmission re-teach by turning the key to #1 position (KOEO). Slowly move the shifter from Park, Reverse, Neutral, and Drive. Then slowly move the shifter back to Park. Hopefully, you will hear some activity coming from the transmission as it learns what gear it should be in. Also, have to tried to pull any DTC's? That may give you a clue as to what might need attention. The other thing you may need is to hook the car up to a Star Tester and reprogram the transmission. Hopefully, you will have access to a Start Tester. If not, maybe you could get your local Mercedes-Benz dealer to help you diagnose why your 453 won't start. There could also be some factory warranty left on this car and these issues could be covered.

I will get the DTC tomorrow, we don't have a local mercedes dealer to take it to. I also might have a local guy I can check to see if he has a star tester.
Thank You

 

[High School Auto Shop]

Update, come to find out the shift mode selector plug was broken so we had to replace the transmission wiring harness. It runs and drives now. The check engine light is on still and has one code. The code is P20B1 (Reductant Heater Coolant Control Valve Circulation).