Suzuki SX4 Diesel: MIL Light & Moisture Sensor Issues

Had a very similar issue with my 2013 Suzuki Swift diesel last year. Have some experience working on cars but mainly basic maintenance stuff. The malfunction indicator light and rough running turned out to be related to a faulty sensor connection. The workshop found corroded wiring and a loose plug connection affecting the water sensor readings. The sensor itself was actually fine, but the sensor fault was triggering due to bad electrical contact. The repair involved cleaning the connector pins and replacing a damaged section of the wiring harness. Total cost was 95€ including diagnostic testing. Since the fix, no more sensor issues or warning lights. To give more specific advice about your case, could you share: Have you noticed any changes when driving in wet conditions? Did you get specific error codes from the diagnostic scan? Has the sensor testing shown intermittent faults or constant issues? Are there any other warning lights besides the malfunction indicator? These details would help determine if your issue matches what I experienced with the sensor fault.

Thanks for sharing your experience. My vehicle has 153570 KM and was last serviced 3 months ago. Your situation sounds quite similar to what I am experiencing. I have noticed the issue gets worse in damp conditions, suggesting a possible connection to moisture sensor readings. The diagnostic scan showed error code P0193, which typically points to sensor issues in the fuel system. The sensor testing showed consistent faults rather than intermittent problems, and the check engine light is the only warning indicator active. The rough running is most noticeable during cold starts. Based on your repair costs, sounds like this might be a manageable fix if the auto electronics issue is similar to what you encountered. Did your mechanic need to order any special parts for the sensor fault repair, or was it mainly labor costs for testing and reconnecting?

Thanks for those details. The symptoms you describe match my Suzuki Swift experience almost exactly, especially the moisture-related issues and rough cold starts. For my repair, the parts cost was minimal since the water sensor itself was functioning correctly. The main expense was diagnostic time and labor for tracing the electrical fault. The mechanic only needed standard wiring supplies to fix the corroded connections causing the sensor issue. One key difference, my car had intermittent malfunction indicator warnings, while yours shows constant sensor faults. This could indicate a more serious wiring problem in your case. The P0193 error code, while related to the fuel system, can sometimes be triggered by a failing moisture sensor affecting multiple systems. Given your higher mileage, it would be worth having the mechanic check the entire sensor wiring harness for deterioration. In my case, what initially looked like a simple sensor fault turned out to involve multiple corroded connections that needed attention. Watch out for increased rough running when weather changes, this is a classic sign of moisture sensor problems affecting the electronics. Consider getting it checked soon before the sensor issue leads to additional complications.

Based on your detailed explanation, I will move forward with getting this checked out. The fact that the issue is constant rather than intermittent does concern me. Your repair experience gives me a good baseline for what to expect, though I realize my wiring issues might be more extensive. The car diagnostics showed that moisture-related problems are definitely affecting the sensor readings. I will ask the mechanic to inspect the entire wiring harness, not just the immediate area around the sensor fault. Since the rough running gets worse in damp conditions, addressing this soon makes sense to prevent additional auto electronics damage. Will book an appointment this week for a thorough sensor testing session. The shop estimates around 120€ for full diagnostics and basic repairs, which seems reasonable compared to your repair costs. Hoping it is just corroded connections like in your case, but prepared for possible additional wiring work given my higher mileage. Will update this thread once I know more about the specific moisture sensor issues they find. Thanks for helping me understand what to expect from the repair process.