Ford Fiesta 2018–2019 — technical service bulletin
Bulletin SSM 47751 · NHTSA communication 10153971 · issued Jan 17, 2019
Technical service bulletin
communication type
Engine
component
2018–2019
model years
2
vehicle entries
Official summary
Some 2018-2019 Fiesta vehicles may exhibit an illuminated MIL with DTC P0128 stored in the powertrain control module (PCM). If the vehicle exhibits this DTC, clear all DTCs and allow the vehicle to sit for a minimum of 3 hours. Then drive the vehicle for at least 16 km (10 miles) and retest for DTCs. If DTC P0128 does not return, do not replace the thermostat valve, release the vehicle at this time. If DTC P0128 returns, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) Manual for normal diagnostics. Engineering is investigating, monitor OASIS for updates.
Vehicles covered
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.