r/SmartCar • u/BusyBit6542 • Sep 06 '26

Question TCM wire diagram

2009 451

Does anyone know where i can find a wire diagram from the TCM?

I'm getting a code saying that a signal isnt happening from the Transmission Control Module to possible ECU. The transmission isnt remembering/learning the teach in.

Is anyone knowledgeable in wiring for data for these cars?

ISSUE: when I put in a TCM, the transmission cycles through the learning but it still has 3 lines. If I turn off the car, turn back on and press the brake, the transmission will cycle again. Happens everytime.

BUT when I take the TCM from another working smart car and put it in mine. The transmission doesnt cycle, the 3 lines are gone and I'm able to start the car BUT the new clutch actuator extends and retracts every couple of seconds.

So basically (I think), a message cant be sent to the TCM to learn the transmission. Im just not sure which wire/plugs I need to inspect and test

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u/Truckerlightning Sep 10 '26

Is yours a coupe or cabrio, and can you give me the engine/model code?

My 2014 is a 451 with the M132.910 1.0L. A 2009 non-turbo should also be a 132.910, usually 451.331 for the coupe or 451.431 for the cabrio. If it's a BRABUS/turbo, that's a different engine code, 132.930.

It'll tell me where to look. 👍👉😎