Diagnostic Aids
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
DTC U0403:00 and U0403:29 indicate a transfer case range message concern. The module reporting this DTC is not the problem module. Do not install a new PSCM as part of the repair for PSCM DTC U0403:00 or U0403:29.
The presence of either DTC prevents the selectable drive mode system (if equipped) from activating. If set while the vehicle is in a drive mode other than NORMAL, the PSCM defaults to NORMAL and the system is disabled.