This bulletin applies to 2017-2019 Lincoln Continental, 2019 Nautilus, 2015-2019 MKC, MKT and MKZ, 2015-2018 MKX and 2015-2019 Navigator models. Some vehicles may experience front or rear park aid sensor false alerts with no diagnostic trouble codes present.
False park aid alerts with no DTCs in the park aid system are usually due to snow, slush, fog, salt, ice, frost buildup, car wash or heavy rain.
Each sensor features a silicone ring designed to absorb vibration and to reduce false alerts. A thin film of ice, etc., may bridge over the silicon ring and/or sensor, causing a false alert.
Upon visual inspection, there may be no obvious obstruction with the sensor. Often, when the vehicle is brought into the service bay, the ice will melt and all evidence of frost/ice will no longer be present.
Diagnostics should be performed but if no DTCs are present, then the ice bridging on the sensor was likely the issue. Verify sensor alignment and ring placement is symmetrical. If no issues are found, advise the customer that this is a normal vehicle characteristic. Advise the customer that they have the ability (on some vehicles) to turn the park aid system off in certain weather conditions.