U1123 - SCP Invalid or Missing Data for Odometer
- 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)
Tech notesThis 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:
Wiring to the vehicle speed sensor breaks or the sensor itself has issues.
When is the code detected?When the 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.
- Engine Light ON (or Service Engine Soon Warning Light)
- O/D Light Flashes Continuously
- Speedometer does not register
U1123 DescriptionThis 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 Information for specific makes
Need more help?Get the U1123 code diagnosed by a professional: Find a repair shop in your area
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