C1123: Vehicle Speed Sensor Input Short to Battery

MediumChassisChassis Electronics

What does C1123 mean?

C1123 is a diagnostic trouble code indicating "Vehicle Speed Sensor Input Short to Battery". A sensor in the chassis electronics is reporting abnormal data or has lost communication with the ECU. Sensors can fail due to age, contamination, heat exposure, or wiring issues.

Common causes

  • Faulty chassis electronics component
  • Wiring or connector issue in the related circuit
  • Failed sensor providing incorrect readings
  • Software/calibration issue requiring ECU update
  • Related component causing secondary fault

What should you do?

Schedule a diagnostic appointment at your earliest convenience. The vehicle is generally safe to drive short distances, but the underlying issue should be addressed to prevent it from worsening.

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Related codes

C1124Input shaft speed signal missing/faulted
C1126Cruise Control Command Switch Assembly Circuit Failure
C1117RPM Input Circuit Failure
C1116Starter Motor Circuit Failure