Volkswagen Passat 2012–2014 — technical service bulletin
Bulletin 26K4 · NHTSA communication 10160483 · issued Jul 17, 2018
Technical service bulletin
communication type
Equipment Adaptive/mobility
component
2012–2014
model years
3
vehicle entries
Official summary
The reductive agent fluid (AdBlue) could contaminate the temperature sensor, causing the Malfunction Indicator Light (MIL) to come on. Additionally, high heat levels can cause the AdBlue fluid to react with the heating fins, causing a variation in internal resistance and the MIL to come on. If the MIL is on, the vehicle will not pass an emissions inspection.
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.