Smart Roadster Gear Display Failure Causes Transmission Havoc

Had the same gear selector issue on a 2006 Smart ForTwo last year. The transmission control unit was failing, causing both the instrument panel display problems and the actual gear shifting issues. Main symptoms matched exactly: grinding during shifts, blank gear position display, and erratic transmission behavior. The control unit affects both the physical shifting mechanism and the electronic display system. The root cause was a defective circuit board inside the transmission control module. While replacing just the affected control unit might seem like a quick fix, the entire transmission needed inspection since metal particles from the grinding had likely contaminated the fluid. In my case, it required: Full transmission control unit replacement, Complete transmission fluid flush, Sensor problem diagnosis and recalibration, New shift knob assembly with position sensors This was a serious repair that took several days to complete. The transmission needed specialized diagnostic equipment to properly sync the new control unit with the car systems. The main warning sign was the gear indicator failing before the transmission started acting up. When these symptoms appear together, it typically points to the control unit rather than just a display issue.

Thanks for the detailed info about the transmission control unit problem. Exact same symptoms I had too. After getting it fixed about 6 months ago, everything has been working perfectly, both the gear indicator on the instrument panel and the shifting itself. Really happy with how the automotive electronics are performing now. Would be helpful to know what you ended up paying for the full repair? Also, have you noticed any other dashboard display issues since the fix? Just want to make sure I budget correctly and know what to watch out for long-term.

After my transmission control unit repair, I have had zero issues with the gear shift indicator or any other electronic display on the car dashboard. The gear indicator shows the correct position every time, and the transmission shifts smoothly without any grinding sounds. The sensor problem that caused the blank display was completely resolved. The total repair cost was 1000€ for the affected control unit replacement and programming. This included the specialized diagnostic work needed to properly integrate the new unit with the vehicle systems. For ongoing maintenance, I monitor the gear indicator display closely since it can be an early warning sign of transmission control issues. But after 6 months, all dashboard electronics continue working perfectly with no new faults appearing. The investment was worth it considering how critical proper gear indication and shifting are for safe driving. Much better to address these transmission control unit problems early before they cause more extensive damage.

Had my transmission control unit replaced last week after dealing with the same issues. The mechanic I went to specializes in automotive electronics and immediately recognized the problem when I described the blank gear indicator and grinding sounds. The repair process went smoothly: Complete diagnostic scan of transmission system, Replacement of faulty control unit, System recalibration and testing, New transmission fluid Total cost came to 1200€ which included parts and labor. The electronic display on my car dashboard is now working perfectly, showing correct gear positions every time. No more grinding during gear shifts either. What really impressed me was how the mechanic thoroughly tested the transmission control unit and gear shift system before returning the car. Been driving for a week now with zero issues, the gear indicator works flawlessly and shifting feels better than ever. Was definitely worth finding a shop that knew what they were doing with these complex transmission electronics. Learned my lesson about not waiting too long when dashboard warning signs first appear.