Dayz bypass valve malfunction

Greetings! An overheating engine coupled with a bypass valve error on a Dayz is definitely concerning. Given the mileage, it's wise to consider potential culprits. First, thoroughly inspect the coolant system for any signs of a leak. A pressure test might be revealing. Next, examine the air intake system for any obstructions or leaks, as this can affect engine performance and temperature. Finally, when was the last time the exhaust system was inspected? A clogged catalytic converter can lead to overheating. Are you experiencing any engine stalling or rough idling alongside the overheating?

Thanks for the detailed suggestions! I'll definitely check the coolant system and air intake more closely. As for the exhaust system, it hasn't been inspected recently. Could a coolant leak really trigger a bypass valve error? Where exactly should I be looking for these leaks?

Indeed, a coolant leak can indirectly trigger a bypass valve error. The engine overheating due to low coolant can cause various sensors to report incorrect data, leading to false error codes. Focus your search for coolant leaks around the radiator hoses, water pump, thermostat housing, and even the head gasket area. Given the age of your Dayz, it would be prudent to have a qualified technician perform a comprehensive diagnostic check to pinpoint the primary cause. It sounds like you are on the right path, but for peace of mind, professional diagnosis would be the best course of action.

Thanks so much for the advice! It was incredibly helpful. Took it to a local shop, and it turned out that, as you suspected, the bypass valve error was indeed a symptom of a larger problem. The mechanic found that the error was stored but not the actual issue. The car runs as expected, and the final repair cost was 0€, as it did not require additional work. I really appreciate your help!