CT4 Trans Grinding & Limp Mode After Sensor Failure

Had nearly identical symptoms with a 2020 CT5. The rough shifting and grinding turned out to be directly linked to a failing pressure sensor at the radiator coolant circuit. The sensor malfunction caused incorrect readings, making the transmission control module activate limp mode as a protective measure. The faulty pressure sensor disrupted the oil cooler function, which is integrated into the cooling system. When the transmission fluid doesnt maintain proper temperature, shifting becomes noticeably rough. Your mechanic is likely correct since these symptoms align perfectly with a cooling system pressure sensor failure. This issue is considered serious since continued driving could lead to transmission damage. The repair required replacing the pressure sensor and clearing the transmission control module codes. The transmission returned to normal operation immediately after the fix. The grinding noise typically occurs when the transmission fluid overheats due to compromised cooling. Worth noting that a coolant leak would show similar warning lights but different symptoms, so the pressure sensor diagnosis makes more sense given your description.

Thanks for sharing your experience. My transmission started working perfectly after the fix. Was wondering how much the sensor replacement cost you? The cooling fan also needed adjustment during my repair, did you have any follow-up issues with the radiator repair or transmission since getting it fixed? Its been 6 months for me with no problems, but I keep a close eye on the transmission fluid temps now.

Had the radiator pressure sensor fixed about a year ago and no issues since then. The complete repair cost 95€ which covered fixing a faulty cable connection to the pressure gauge, turned out replacement wasnt needed, just the connection was bad. The cooling system has worked flawlessly after the repair. Good call monitoring the transmission fluid temps. The pressure sensor plays a crucial role in the cooling system operation, and when its working correctly, the transmission should maintain proper operating temperature. My mechanic cleared the transmission codes after the repair which resolved all warning lights and rough shifting symptoms. No cooling fan adjustments were needed in my case, but its common for techs to check the entire cooling system when addressing pressure sensor issues. Regular coolant level checks and watching for any warning lights is still a good practice, even though these fixes tend to be permanent when done right.

Fixed my transmission issue last week and wanted to share the outcome. The pressure sensor repair went smoothly, mechanic found the problem exactly where they said it would be. Total bill came to 420€ including labor and parts. The cooling fan needed a small adjustment during the fix which added some time, but they did a full leak detection test to make sure everything was sealed properly. The oil cooler lines were also checked and thankfully showed no issues. Been driving for a few days now and the transmission is back to normal, no more grinding or rough shifts. The warning lights are gone and it feels like a different car. Started keeping a log of transmission temps just to stay on top of things, but so far everything looks perfect. Really glad I got this sorted quickly instead of waiting. The mechanic mentioned catching it early probably prevented more serious transmission damage that could have cost thousands to fix.