DTC U2142-00: Communication Error With Microphone [Connectivity Master Unit (Us)]: Outline

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DTC U2142:00 (CONNECTIVITY MASTER UNIT - US) DETECTION CONDITION AND POSSIBLE CAUSE

System malfunction location	Communication error with microphone
Detection condition	The connectivity master unit (CMU) detects a response error from the microphone, and even though retries and relaunches are performed continuously for approx. 60 s, the malfunction condition continues.
Fail-safe	If there is a malfunction in control circuit: If it does not return to normal even though the power supply for the microphone is turned on/off repeatedly for the specified number of times, it is determined that the microphone is undetected, and the operation continues. If a communication error is detected and when it does not return to normal even though the power supply for the microphone is turned on/off repeatedly for the specified number of times, it is determined that the microphone is undetected, and the operation continues. The microphone setting value is periodically verified and if there is a malfunction, a setting value that protects the connectivity master unit (CMU) is set. If there is a malfunction in power supply circuit: If it does not return to normal even though the power supply for the microphone is turned on/off repeatedly for the specified number of times, it is determined that the microphone is undetected, and the operation continues. The microphone setting value is periodically verified and if there is a malfunction, a setting value that protects the connectivity master unit (CMU) is set.
Possible cause	Microphone connector or terminal malfunction Connectivity master unit (CMU) connector or terminal malfunction Short to power supply, short to ground or open circuit in microphone power supply circuit Open circuit in microphone ground circuit Short to power supply, short to ground or open circuit in microphone control circuit Microphone malfunction Connectivity master unit (CMU) malfunction
Courtesy of MAZDA MOTORS CORP.