Buick Century TCU Failure Symptoms and Solutions

I had similar transmission problems with my 2003 Buick Regal, and as someone with some hands-on experience working on cars, I can relate to your situation. The symptoms you describe match exactly what I experienced, transmission slipping, harsh shifting, and transmission control issues. After proper transmission diagnosis at my workshop, they found the transmission control module was indeed defective and needed replacement. The repair involved: Complete diagnostic scan, Removal and testing of the control module, Installation of a new transmission control unit, Reprogramming and calibration, Final testing to ensure proper gearbox function Total cost was around 1000 for parts and labor, but it completely resolved the transmission problems. The car shifted smoothly again after the repair. Before jumping to conclusions though, could you share: Current mileage on your Century? Are there any other warning lights active? When was the last transmission fluid change? Which specific error codes is the computer showing? This information would help determine if your issue is identical to what I experienced or if there might be other underlying transmission control issues that need attention.

Last service was done at 68086 KM, I replaced the transmission fluid and filter then. No other warning lights currently showing on the dash. The transmission control module shows error codes P0218 and P0730, pointing to problems with the transmission. The mechanic quoted almost double what you paid, which seems excessive for replacing a control module. Anyone else had experience with these specific transmission codes on their Century? Trying to decide if I should get a second opinion on the diagnosis and repair costs.

Thanks for providing those details. When I had my Buick fixed, I initially got quotes ranging from 900-2100 Euro, so I understand your concern about the repair costs. Those exact error codes (P0218 and P0730) showed up on my car too. In my case, the automotive ECU diagnostic confirmed it was definitely the transmission control unit causing the problems. But before replacing the entire unit, my mechanic found that cleaning the electrical connections and checking the wiring harness resolved some of the gearbox issues. The price difference might be due to: Parts availability, Labor rates, Whether theyre using OEM or aftermarket parts, Additional services included in the quote Getting a second opinion is always smart with major automatic gearbox repairs. When I shopped around, I found a shop that specialized in transmission problems who did the work for significantly less than the dealer quoted. Based on your mileage and maintenance history, your transmission should still have plenty of life left once the control issues are sorted. Just make sure whoever does the work can properly program the new unit, incorrect programming can lead to more gearbox issues down the line.

Based on your input and quoted repair costs, I think getting that second opinion makes sense. The transmission fluid and filter were recently changed, so at least I know those aren't causing the current problems. These error codes definitely point to transmission control unit issues, but I want to ensure I'm not overpaying for the repair. My main concern is finding a shop that has experience with transmission diagnosis and programming these specific control modules correctly. I'll call around to a few transmission repair specialists tomorrow and get detailed quotes. Having P0218 and P0730 codes will help them provide more accurate estimates. Will also ask about their experience with Century transmission problems and make sure they can properly program the new control unit if that ends up being necessary. Thanks for sharing your repair experience, it helped confirm I'm likely dealing with a control module issue rather than internal transmission problems. The repair costs you mentioned give me a good benchmark when comparing quotes from different shops.