U1950 Code: Meaning, Causes, and Symptoms | OBD2 Codes

U1950 – UPB Communication Bus Fault

 

U1950 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light),Engine won鈥檛 start 鈥 won鈥檛 crank,ABS Warning Light ON,Transmission may shift erratically,Cluster won鈥檛 register any reading

 

U1950 Possible Causes

 

UBP Bus wiring intermittently open/shorted to power or ground,Faulty / intermittent electrical connection at any of the controllers on the UBP network

 

U1950 Description

 

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.