DTC U034B: Software Incompatibility with Brake Booster Control: Action
WARNING: This page is about a different car, the 2020 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
CHECK the service history for recent service actions related to the PCM. This DTC sets due to incomplete or improper PMI procedures. If there have been recent service actions with the PCM, REPEAT the PMI procedure as directed by the diagnostic scan tool. CLEAR the DTC and CARRY OUT the PCM KOEO self-test. If the DTC does not return, the repair is complete. If the DTC returns, INSTALL a new PCM. REFER to the appropriate Electronic Engine Controls article.