U1950 - UPB Communication Bus Fault
UBP Bus wiring intermittently open/shorted to power or ground
Faulty / intermittent electrical connection at any of the controllers on the UBP network
This is typically an electrical wiring connection issue at one of the controllers being monitored by the manufacturer.
It can occur if:
Wiring to the module becomes shorted by the module.
Wiring to the module becomes shorted between modules, such as where wires are routed on passenger side floor rails and become water soaked. Watch for water intrusion when this occurs.
When is the code detected?
When the controllers are unable to communicate with each other at any time while the ignition switch is turned to the “Run” position.
Engine Light ON (or Service Engine Soon Warning Light)
Engine won’t start – won’t crank
ABS Warning Light ON
Transmission may shift erratically
Cluster won’t register any reading
The Anti-lock Brake System (ABS) module, the Powertrain Control Module (PCM
), the Transmission Control Module (TCM), the instrument cluster and the parking aid module are just some of modules that communicate over the UART Based Protocol network bus or UBP Bus. This is a high-speed bus communication system and is not fault tolerant, which means any type of intermittent/loose connection between these 3 controllers will cause communication to stop. When the PCM
, ABS module and instrument cluster are unable to communicate with each other at any time while the ignition switch is turned on, code U1950 will set.