Cadillac STS Steering & ABS Issues: Multiple Warning Signs

As someone with some car repair experience, I dealt with a very similar issue on my 2009 Cadillac CTS. Initially thought it was multiple problems, but it turned out the root cause was a faulty tire sensor and pressure loss in one wheel. The tire pressure warning was the first sign, but I initially ignored it after checking with a tire gauge and adding air. The pressure kept dropping slowly, and then the ABS and steering issues started showing up. A proper inspection revealed a defective tire valve that was causing a slow air leak. The vibration you describe matches exactly what I experienced, it happens because the tire pressure sensor system interfaces with the ABS and power steering systems on these models. When one system shows an error, it can trigger warnings in the others. The total repair cost in my case was 280€, which included: Replacing the defective valve, Recalibrating the tire sensor, System diagnostic check, Resetting warning lights Before suggesting more specific solutions, could you share: Current tire pressure readings on all wheels, Whether the pressure loss is constant or intermittent, If you notice any punctured tire or visible damage, Whether the problems started simultaneously or one after another This information would help determine if you are dealing with the same root cause I had.

Thanks for checking all the suggestions. Recent service was actually done at 151000 KM, so pretty recent. I checked all tire pressures today and you might be onto something. The front right tire shows significantly lower pressure than others, suggesting a punctured tire causing gradual pressure loss. This makes sense given the steering pull and vibration getting worse over time. Worth noting the tire sensor warning started about a week before the ABS light, which fits with your theory about interconnected systems. I will get the front right tire checked first since fixing a flat tire or sensor issue would be cheaper than diving into ABS repairs right away. Interesting that your repair cost was 280€. Hoping mine ends up in a similar range rather than needing more extensive work.

Thanks for the pressure check update, your symptoms match my experience even more closely now. The one-week delay between the tire warning and ABS light is exactly what happened with my Cadillac CTS. A significantly lower pressure in that front right tire definitely explains the steering pull. When I had my flat tire issue, the tire monitoring system first detected the pressure loss, and as it got worse, it affected the ABS readings which rely on consistent wheel speeds and pressure. My mechanic explained that inflated tires at the correct pressure are crucial for these systems to work properly. The tire pressure sensor communicates with multiple vehicle systems, so when it detects an issue, it can trigger various warning lights. Quick suggestion before you take it in, document the pressure readings from all tires and note how quickly the front right loses pressure. My repair cost stayed reasonable at 280€ because we could pinpoint the issue quickly. The tire sensor replacement might not even be needed if its just a simple puncture repair. Watch out for any further changes in steering feel or vibration while you schedule the repair. In my case, letting it go too long risked damaging other components.

Thanks for all the feedback. Just wanted to update that I took it in for service today. Mechanic found a small nail causing an air leak in the front right tire, exactly where the tire sensor was showing the problem. Got really lucky, total repair cost was only 95€ for the puncture repair and system check. The mechanic confirmed the air leak triggered those other warning lights, just like you experienced. Once they fixed the flat tire and reset everything, both the ABS and steering warnings cleared up completely. The vibration is totally gone now and steering feels normal again. Good call on checking the tire pressure first, saved me from unnecessarily replacing ABS components or other expensive parts. Also learned how a simple pressure loss in one tire can mess with multiple vehicle systems. Really glad I asked here before assuming the worst. Will definitely pay more attention to tire sensor warnings in the future, knowing how they connect to other systems.