DTC C1721[12] Front Left Turn Signal Light Output Circuit Short to Battery (BCM)

1. DTC C1721[12] description

When the turn signal switch signal or hazard warning flasher switch signal is input, the BCM controls the turn signal light output circuit and illuminates the turn signal light. If the BCM detects a malfunction in the turn signal light (front left) output circuit, the DTC is set.

2. Condition for setting DTC C1721[12]

Condition for running the DTC

  • The BCM commands the turn signal light (front left) OFF.

Condition for setting the DTC

  • The BCM detects a short to the power supply in the turn signal light (front left) output circuit.

3. Action taken when DTC C1721[12] sets

  • The output of the turn signal light (front left) is turned ON regardless of the input turn signal switch signal or hazard warning flasher switch signal.
  • Current and past failures are set.