VW Phaeton Oil Pressure Warning Lamp Issues & Fixes

I had a similar issue with my 2009 VW Passat and can share my experience dealing with oil pressure warnings and car sensor problems. The car diagnostics revealed that the engine sensor was indeed causing false readings, but not the engine temperature sensor itself. In my case, the workshop found a damaged cable connection to the oil pressure sensor, which was triggering erratic readings and warning lights on the dashboard. The repair involved checking all sensor connections and replacing a damaged wiring connector. Total cost was 95€ for the repair, including labor and parts. Since then, the warning lights have stayed off and the oil pressure readings returned to normal. Before suggesting specific solutions for your Phaeton, it would help to know: What error codes are stored in the system? Does the warning appear more frequently when the engine is cold or at operating temperature? Have you noticed any actual oil pressure or temperature issues? Are there any other warning lights appearing alongside? These details would help determine if your issue matches what I experienced with the faulty sensor connection or if it might be something different.

Last service was at 37500km and oil level is correct according to the dipstick. Thanks for sharing your experience. The stored error codes are P0520 and P0523. The warning typically appears after the engine reaches normal operating temperature, never when cold. The automotive sensor readings show normal oil temperature values until just before the warning appears. No other warning lights appear alongside, just the oil pressure warning in the cluster. Will get the engine sensor connections checked based on your feedback. The intermittent nature of the issue does point toward a possible wiring problem rather than complete oil sensor failure.

Thanks for providing those additional details. Based on the error codes P0520 and P0523, my experience with the wiring issue on my Passat seems even more relevant to your situation. Those specific codes typically point to an oil pressure sensor circuit problem rather than an actual oil pressure issue. The fact that your warnings appear only at operating temperature matches what I experienced, heat would cause the damaged wire connection to act up once the engine bay got warm. Since you confirmed normal oil levels and the sensor readings appear fine until just before the warning, this strongly suggests an electrical fault rather than a mechanical oil pressure problem or temp sensor failure. In my repair, the workshop located the faulty connection by performing targeted engine sensor diagnostics while the engine was warm. The intermittent nature and timing of the warnings match my case exactly. The repair cost might be similar to what I paid (95€), though it depends on how accessible the wiring is in your model. The good news is that these wiring repairs typically provide a permanent fix once properly diagnosed and repaired. I recommend having a shop specifically check the wiring harness and connections around the oil pressure sensor, as addressing just the engine temperature sensor might not resolve the root cause.

Thanks for the detailed feedback and sharing your Passat experience. The matching symptoms with the error codes P0520/P0523 appearing at operating temperature really helps confirm we are likely dealing with the same type of issue. The oil sensor wiring problem makes a lot of sense given the intermittent nature. Since our cases are so similar with the temperature-dependent warnings and normal oil pressure readings until the fault occurs, I will definitely have the shop focus on checking those sensor connections first. The repair cost around 95€ seems reasonable if it permanently resolves the warning lights. I will schedule an appointment to have them run diagnostics specifically on the oil pressure sensor circuit and inspect the wiring harness. Hopefully they can locate any damaged connections when the engine is warm, just like in your repair. Really appreciate you taking the time to explain your experience, it has helped narrow down where to look for the root cause rather than just replacing parts.