GMC Savana: Slipping Trans & Limp Mode Trouble Signs

Having experienced similar symptoms on my GMC Sierra 2003 Diesel at 85000 KM, this sounds like a classic case of degraded transmission fluid and potential electronic control issues. The automatic transmission requires clean hydraulic fluid to function properly. When I had these symptoms, the transmission performance was severely compromised due to contaminated fluid and worn-out transmission components. The slipping between gears and limp mode activation are serious warning signs that should not be ignored. A transmission flush was only part of the solution in my case. The problem also required: Replacement of transmission solenoids, New transmission filter, Repair of electrical connections, System pressure test This turned out to be a major repair requiring specialized transmission equipment. Attempting to drive with these symptoms risks complete transmission failure. The warning lights and limp mode are protective measures to prevent catastrophic damage. A qualified transmission specialist should perform a full diagnostic. While a basic transmission fluid change might help if caught early, your symptoms suggest more extensive wear. The lack of regular fluid maintenance has likely accelerated the wear of internal components. Getting this fixed properly now will prevent more costly repairs later. This is not a repair to postpone or attempt as a DIY project given the complexity of modern automatic transmissions.

Thanks for sharing your experience. After my recent slipping transmission issues, I also had similar repairs done on my Savana. Good to hear the transmission specialist found the root cause in your case. Would you mind sharing how much you ended up paying for the complete repair? Im curious if the final cost was in line with what I paid. Also, has your automatic gearbox been running smoothly since the fix, or have you noticed any recurring problems? In my situation, the transmission oil change alone didnt solve it, but knowing the total cost range for these repairs would help others facing similar issues.

Thanks for asking about the repair costs. After getting everything fixed on my GMC Sierra, including the automatic transmission fluid replacement and addressing the undervoltage issue, the transmission has been working flawlessly. The total bill came to 240 Euro for the electrical repairs, which was actually less than I expected given the symptoms. The slipping transmission problems completely disappeared after the repair. The hydraulic fluid change made a huge difference in how smoothly the gears shift now. I havent experienced any warning lights or limp mode incidents since the fix, and its been several months of trouble-free driving. For others dealing with similar transmission problems, its worth noting that getting a proper diagnosis from a transmission specialist can save money in the long run. While my repair costs were relatively modest at 240 Euro, catching these issues early prevented more extensive transmission damage that could have been much more expensive to fix. The car transmission now shifts perfectly between gears, and the electronic issues that were causing the undervoltage have been completely resolved.

After all your helpful replies, I wanted to share how my repair experience turned out. I finally took my Savana to a different transmission specialist who properly diagnosed the issue. The slipping transmission turned out to be caused by both degraded transmission oil and faulty solenoids. The total repair cost came to 1850 Euro, which included: Complete transmission oil replacement, New solenoids, Filter change, Labor costs While it was more expensive than just an oil change, the automatic gearbox now shifts perfectly. No more warning lights or limp mode issues. The specialist explained that the lack of regular transmission oil changes had caused excessive wear, but catching it before complete failure saved me from needing a full transmission rebuild. The repair took 3 days to complete, but it was worth the wait and cost. Been driving for 2 months now without any transmission problems. Learned my lesson about regular maintenance, will definitely keep up with scheduled transmission service from now on.