Subaru Impreza 2017–2019 — technical service bulletin
Bulletin 07-140-18 · NHTSA communication 10150908 · issued Oct 9, 2018
Technical service bulletin
communication type
Electrical System
component
2017–2019
model years
3
vehicle entries
Official summary
This bulletin announces an additional troubleshooting step to follow when diagnosing a DTC U0284: ?LOST COMMUNICATIONWITH ACTIVE GRILLE SHUTTER MODULE ?A?. Water intrusion into the harness wiring leading to connector B63 for the Active Grille Shutter (AGS) may lead to corrosion of the harness wiring and/or connector terminals and result in a communication loss with the ECM.
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.