Engine-Codes - Generic - U1123

U1123 Code - Invalid Or Missing Data For Odometer

- Code Popularity: 35,702 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
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What are the Possible Causes of the DTC U1123?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty / intermittent vehicle speed sensor / connections
  • J1850 / SCP / CAN Bus wiring intermittently open, shorted to power or ground
  • Faulty / intermittent connection at the Powertrain Control Module (PCM)
  • Faulty / intermittent connection at the Anti-Lock Brake Module (ABS)

Code Tech Notes

This is typically an electrical wiring connection issue, either at the engine controller or at the sensors being monitored by the manufacturer.
It can occur if the wiring to the vehicle speed sensor breaks or the sensor itself has issues.

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How to Fix the DTC U1123?

Check 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 pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the U1123 code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

When the Powertrain Control Module (PCM) is unable to communicate with any other controller on the bus network at any time while the ignition switch is in the RUN position.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • O/D Light Flashes Continuously
  • Speedometer does not register

What Does the U1123 Code Mean?

This is a manufacturer specific fault code and can be used for several different faults, depending upon what the manufacturer wants to use it for. Controllers communicate over the Serial Communication Protocol (SCP) bus network, also known as J1850 bus, or Controller Area Network or CAN Bus. These bus communication systems may or may not be fault tolerant, which means any type of intermittent/loose connection between these controllers could cause communication to stop. When these controllers are unable to communicate with each other at any time while the ignition switch is turned on, code U1123 will set.

U1123 Code - Invalid Or Missing Data For Odometer

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Code U1123 Information for Specific Makes

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