Oil Warning Lights Signal Sensor System Malfunction

I had a similar issue with my 2011 Buick LaCrosse last winter. As someone with moderate automotive experience, I can tell you these oil warning signals can be quite misleading when theres actually a sensor issue involved. After checking the engine oil level manually and confirming it was fine, I suspected a faulty sensor or connection problem. The automotive oil monitoring system was giving incorrect readings, similar to your situation. Took it to a workshop where they diagnosed a damaged wire connection to the oil pressure sensor. The cable had worn out over time, causing intermittent false readings. They replaced the wiring harness and properly secured the connection. Total repair cost was 95 Euro, and the warning lights havent returned since. Before jumping to conclusions though: Does the warning light stay on constantly or flicker? Have you noticed any unusual engine sounds? What error codes is the system showing? Any recent car maintenance work done near the sensor area? This info would help determine if youre dealing with the same sensor issue I experienced or if its something different.

Latest service was at 185000 KM. Thanks for sharing that detailed experience. The warning light stays constant after the engine warms up. No unusual engine sounds noticed. Getting error code P0521 which points to an oil pressure sensor circuit issue. The oil detection system seems to be malfunctioning rather than showing actual oil problems, since manual checks show proper levels. Just curious, did your repair also involve updating any engine control modules, or was it purely a wiring fix? Trying to gauge if this will need more extensive work than just replacing connections.

The repair for my LaCrosse was primarily focused on the wiring harness, no ECM updates were needed. Looking back at my service records, they did conduct a full system diagnostic after the repair to ensure the oil gauge and sensor communication were working properly. Since youre getting the P0521 code specifically, this matches the symptoms I experienced almost exactly. The oil signal issues typically stem from either the wiring connection or the pressure sensor itself. In my case, the constant warning light after warm-up was a classic sign of a wiring fault rather than a bad sensor. The repair was straightforward: Tested the oil pressure sensor circuit, Located the damaged wire section, Replaced the affected portion of the harness, Verified proper signal transmission My mechanic noted that on these models, the wiring near the oil pressure sensor often deteriorates due to engine heat exposure. Once fixed, the system should return to normal operation without needing any additional module updates or programming. Given your similar symptoms and error code, Id bet youre dealing with the same faulty sensor circuit issue. The fact that your engine oil levels check out manually further supports this diagnosis.

Thanks for the thorough explanation about the wiring harness repair. This helps narrow down my likely issue with the oil pressure sensor and monitoring system. Great to hear your fix was relatively straightforward without needing complex ECM updates. I scheduled an appointment to have the wiring and oil sensor circuit checked out. The constant warning light and P0521 code really do seem to match your experience exactly. Regular car maintenance has kept everything else running well, so hopefully this is just an isolated wiring problem like in your case. Will update once I get the diagnostic results, but feeling more confident now that this is a known issue with a clear fix. Appreciate you sharing the detailed repair steps, helps me know what to expect when I take it in.