C1233 – Left Front Wheel Speed Sensor Input Signal Missing

Meaning:

When the PCM or vehicle speed sensor (VSS) has failed to receive signals from the Left Front Wheel Speed Sensor, the C1233 happens
The C1233 is triggered when the PCM or vehicle speed sensor (VSS) has failed to receive signals from the Left Front Wheel Speed Sensor

The PCM or vehicle speed sensor (VSS) has failed to receive signals from the Left Front Wheel Speed Sensor.

Main Symptoms:

Possible Causes:

  • Poor connection in Left Front Wheel Speed Sensor
  • Open, shorted or broken wire in Left Front Wheel Speed Sensor harness
  • Defective Left Front Wheel Speed Sensor

Diagnostic Steps:

  • Visually inspect all wiring in the Left Front Wheel Speed Sensor circuit for loose, open or short connections
  • Perform resistance test on Left Front Wheel Speed Sensor. Replace if necessary
  • Reset code and do drive cycle, if it returns probe ABS system entirely

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