Engine-Codes - Generic - U1950

U1950 - UPB Communication Bus Fault

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

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

How is the U1950 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Tech Notes

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.

What is the cost to diagnose the U1950 code

Labor: 1.0

The cost to diagnose the U1950 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
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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.

Possible Symptoms

  • 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

U1950 Meaning

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.

More Information

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Information for specific makes

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