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Gearbox actuator not working

1319 Views 2 Replies 2 Participants Last post by  martinsmart
Hello !
I have real drama with my Smart Fortytwo 1.0i 52 kw 2014 .
Will try to be less confusing as possible .
So ... the car were waterdamaged and the TCU got burned . After replacing the TCU with other one , most of the functions of the gearbox came back to life . The biggest problem is the error code stored in the TCU : The gearbox can't do relearning . After some oki-poki with Star Diagnosis I found out that actuator 1 ( M17 ) is not getting engaged from the TCU , while actuator 2 ( M18 ) is working properly . I tried moving the gear by hand and on live data , the TCU is seeing the degrees changing on actuator 1 ( the problem one ) , but still it doesn't want to make it move , so to go through the relearning process . I tryed providing direct ground and supply to the actuator and it moves , so for sure the actuator is OK . But still ...
The TCU was replaced in a shop that claims that they code it to the car VIN number , but for sure they didn't done it , because in the Star Diagnosis when I check the info for the TCU the VIN number is totally different from my car . So several questions come to my head :

1. Because the TCU is not matched to the car , is it possible , the actuator to not be commanded because of that ?
2. Is there any specific way to install the actuator body in the gearbox , because i can see some arrow marks on the gears of it ?
3. I checked all the grounds , supplies and CAN communication wires that goes to the TCU and everything checks OK , but still I don't have wiring diagrams for the TCU and the gearbox actuators/sensors to be 100% sure of my diagnosis . Is it possible someone to share wiring diagrams about this installation ?

And before someone asking for the clutch actuator ... yes it is working . The main problem is that the TCU is not sending supply to the actuator 1 ( M17 ) , not sure is there any other checks i forget to do , before condeming the TCU ones again .

Thanks in advance !
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Welcome to SCoA! :)

There appears to be a Mercedes-Benz dealer near your location. It may come down to taking the car to them.
Thanks jwight !
The idea is , to try to diagnose the car by myself and then to take the car to them , to just code the TCU if needed .
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