Ccrosser transmission control unit failure

Wow, that sounds frustrating! I had similar transmission problems with my old Vauxhall Insignia. The gearbox was slipping like crazy, especially between 3rd and 4th. The error codes pointed to the transmission control module, but I initially suspected the solenoids. Did you check those before condemning the entire unit?

You mentioned checking the solenoids on your Vauxhall. Can you elaborate on the diagnostic procedure? What parameters did you monitor, and were there readings that pointed away from the TCM and towards a solenoid issue?

I'm no expert, so take this with a grain of salt. I relied on online forums and a mechanic friend. We used an OBD scanner to monitor the solenoid activity while driving. The readings were erratic and didn't match the expected values for the gear position. We were hoping it was just a solenoid, but the mechanic confirmed that the TCM itself was faulty. Given your symptoms and stored error codes, it really does sound like the control unit. I'd recommend getting a professional diagnosis before throwing parts at it, though.

Thanks for sharing your experiences. Your insights regarding the Vauxhall and the solenoid checks were helpful. I consulted with a trusted workshop, and their diagnostic assessment aligns with our initial suspicions: a defective transmission control unit. A replacement has been ordered. While the cost is substantial, your input provided valuable context and confidence in pursuing the correct repair path.