Conditions for Setting the DTC

B127C 02 

The radio detects a short to ground in the microphone high signal circuit for 5 s or greater.

B127C 04 

The following conditions will set this DTC:

• The radio detects an open/high resistance in the microphone high signal circuit for 10 s or greater.
• The radio detects an open/high resistance in the microphone low signal circuit for 10 s or greater.