Kalos Transmission Sensor Triggers Limp Mode & Grinding

I faced nearly identical transmission issues with my 2011 Chevy Spark last summer. The symptoms matched exactly, transmission warning light, limp mode, and rough gear shifting. After diagnosis, it turned out to be a combination of low transmission fluid and a faulty temperature sensor. The transmission sensor was sending incorrect readings, which caused the transmission control module to get confused. But the root cause was actually the low fluid level, which led to overheating problems. The repair involved: Replacing the oil sensor, Full transmission fluid flush, Installing new transmission filter, Recalibrating the transmission control module It was a serious issue that needed immediate attention since low fluid levels can quickly destroy a transmission. The grinding sounds you're hearing are particularly concerning, they suggest internal damage may already be occurring. Rather than just replacing the sensor, I'd recommend getting a complete transmission diagnostic. The symptoms point to potentially more extensive issues that should be addressed before they get worse.

Had the exact same transmission issues you described with my Kalos a few months back! That grinding sound really got me worried too. The sensor replacement fixed most problems, but I discovered a small leak that was causing the transmission oil level to drop gradually. Would be super helpful to know how much your repair ended up costing and if you've noticed any other transmission issues since the fix? My bill seemed a bit steep and I'm curious to compare. Also wondering if your mechanic mentioned anything about preventative maintenance to avoid future problems?

Thanks for asking about the follow-up! After getting my Spark fixed, everything's been running perfectly with no transmission issues whatsoever. The faulty transmission oil temperature sensor replacement was spot-on, and fixing the gearbox oil level solved those worrying grinding noises completely. The total bill came to 365€, which covered both the sensor replacement and topping up the transmission fluid. While it might seem steep, it was worth every penny considering the potential damage that could've happened to the transmission if left unfixed. The mechanic recommended checking transmission fluid levels every 30,000 km and watching for early warning signs like unusual gear shifting patterns or transmission warning lights. They also suggested listening for any odd noises during gear changes, apparently, catching issues early can save a ton on repairs. Definitely glad I didn't wait longer to fix it. The automatic transmission has been shifting smoothly since the repair, with no overheating problems or warning lights. Make sure to keep an eye on that leak you mentioned, even small ones can lead to bigger transmission issues if the fluid level drops too low again.

Thanks everyone for the advice! Just wanted to share how my repair went. After reading the responses here, I took my Kalos to a new mechanic who specializes in automatic transmissions. Good call on getting a complete diagnostic, turns out I had both a faulty temperature sensor and a cracked transmission oil line causing the leak. Total repair came to about 450 for parts and labor: New transmission sensor, Replacing the leaky line, Fresh transmission fluid, System diagnostic The grinding noise completely disappeared after the fix. The mechanic showed me how to check the transmission oil level myself and recommended doing it monthly. Been about three weeks since the repair, and the transmission's shifting like new, no warning lights or rough changes. Big thanks for pushing me to get it checked properly instead of just replacing the sensor. Definitely saved me from bigger transmission issues down the road.