U019D on MINI: How to Diagnose & Fix
Lost Communication With Direct Ozone Reduction Catalyst Temperature Sensor
1 MINI model · 1 documented issue · $1,200-$3,700 repair
U019D on MINI by model: symptoms, diagnosis and fix
F54 Clubmans built with the EAC-coated radiator carry an air-quality sensor permanently mounted to the radiator core. MINI service information (SIM 13 01 19) identifies that the chemical composition of the cooling fan shroud contaminates the EAC sensor, and corrosion over time kills LIN-Bus communication with it, storing fault FC1B8302 / U019D and lighting the check engine light. Because the sensor is not separately serviceable, the fix is a complete radiator replacement, which owners have been quoted at over $3,000. Separately, MINI USA bulletin SIM 01 05 20 extends the EAC sensor's emission warranty to 15 years/150,000 miles from the in-service date, but only on 2016 Cooper S Clubmans with the B46M PZEV engine built August 2015 to June 2016 (cars registered in California-PZEV states already get the same coverage as standard), so coverage depends on the engine and build date rather than the region, though some owners report being denied.
Common Symptoms
- Check engine light with no drivability change
- Loss of communication with air quality sensor
- Recirculation / air quality function behaves oddly
- Dealer quotes full radiator replacement for a sensor fault
How to Fix
Replace the radiator with the integrated EAC sensor, and replace the cooling fan shroud if it is the contaminating original design, per MINI's service measure. Ask the dealer to check your VIN for the SIM 01 05 20 EAC sensor warranty extension (15 years/150,000 miles from the in-service date) before paying out of pocket - some owners have had it covered well past the base warranty.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (2)
U019D code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does U019D mean on a MINI?
U019D stands for "Lost Communication With Direct Ozone Reduction Catalyst Temperature Sensor." A control module on the LIN or CAN bus stopped receiving valid messages from the direct ozone reduction (DOR) catalyst temperature sensor. On BMW and MINI this sensor is the radiator-mounted Environmental Air Catalyst (EAC / PremAir) coating sensor, which reports the temperature of the ozone-reducing catalyst layer applied to the radiator core. The module sets the code when the expected periodic sensor message is absent, corrupt, or fails the bus timeout threshold, so the DOR catalyst function can no longer be monitored. On MINI it is documented across 1 model: Clubman.
What are the most common causes of U019D?
The most common causes of U019D are: Failed radiator-mounted EAC / direct ozone reduction catalyst temperature sensor, Open, shorted, or corroded LIN-bus signal wire between the sensor and the controlling module (front-end position exposes it to road salt and water), Corroded or water-intruded sensor connector at the radiator, Loss of supply voltage or ground to the sensor, Radiator replaced without transferring or reconnecting the EAC sensor. The specific cause varies by vehicle.
How much does it cost to fix U019D on a MINI?
Published repair estimates on MINI range from $1,200 to $3,700 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for U019D on a different make?
View U019D across all makes →Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.