P05C1: Keep grille shutter B thermal faults separate from its other subtypes

P05C1 can be an incomplete description unless its failure subtype is retained. In the cited Ford summary, P05C1_4B denotes active grille shutter module B overtemperature, while other P05C1 suffixes identify coil and supply-voltage conditions. The shared base code does not make those faults equivalent.

Temperature is measured inside the actuator

For the thermal monitor, the actuator controller’s ASIC junction temperature must exceed 140°C. The check runs continuously, has no additional entry condition listed, and uses a 30-second failure-registration period. These are internal controller criteria rather than an external housing-temperature measurement.

The separate low-supply branch uses a different internal quantity and a battery-voltage enable window. An electrical supply observation therefore cannot stand in for the temperature evidence simply because the scanner’s shortened display is similar.

Build a record around the thermal event

Confirm that module B and the thermal subtype are actually reported, then preserve the event state and any contemporaneous supply or coil faults. Simultaneous classifications may guide further investigation, but none proves the others caused the overheating.

A temperature that has returned to normal after shutdown does not recreate the published sustained condition. The source does not support heating the actuator, forcing its mechanism, or replacing it solely from the base code. The applicable vehicle procedure is needed to distinguish the cause of the internal thermal report while preserving the exact fault identity.

Source and applicability

Ford 2024–2025 gasoline OBD summary, July 16, 2024 revision; only the described monitor and architecture. Model, engine and calibration fitment are not inferred. The monitor explanation does not identify a failed part or replace the applicable service procedure. Ford PDF, page 127. Ford PDF, page 128. Ford PDF, page 129.