Customer may report that the vehicle does not start due to a discharged battery. DTC U101100 (supply voltage too low) is stored in the gateway, J533 (address word 19), and/or the electronic parking brake (EPB) control module, J540 (address word 53). According to the test plan "19-Read Data Bus Keep-Awake Manager", the EPB control module kept the data bus active for prolonged periods of time. The EPB switch appears to be permanently operating (applying or releasing the parking brake) due to an internal mechanical issue or because it is jammed or blocked by debris or by a foreign object. Test plan "19-Read Data Bus Keep-Awake Manager", identifies the EPB control module as keeping the data bus active for prolonged periods of time.