The presence of error P1804 ("Gearbox fault") indicates a thermal protection of the clutch engaged. Peugeot 207 with box 2-Tronic is quite common. It may be caused by a malfunction of the RFC, and it may be caused by the vehicle operation.
Given that there is no temperature sensor in the body of this node, it is impossible to talk about overheating. To determine the cause of a problem, you must contact a specialized service whose wizard has the experience of repairing the type of checkpoint.
