P2C78
Active Grille Air Shutter Module D Over Temperature
The control module of active grille air shutter D reports junction temperature above its protection threshold. Thermal protection has triggered.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Under-bonnet temperature too highCommon
- Sustained stall currentPossible
Parts involved
- Active Grille Shutter D
- Wiring Harness
- ECM
P2C78 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.