Troubleshooting diagnostic procedure

U2142-00: (CMU) TROUBLESHOOTING AND POSSIBLE CAUSE (WITHOUT EMERGENCY CALL SYSTEM)

Step	Inspection	Results	Action
1	PURPOSE: VERIFY REPEATABILITY Switch the ignition ON (engine off or on)/main power ON (READY off or on). Clear the DTC recorded in the memory. (See CLEARING DTC .) Switch the ignition off/main power OFF, and then switch it ON (READY off or on) and wait for 30 s or more. Perform the DTC inspection for the connectivity master unit (CMU). (See DTC INSPECTION .) Is the same Pending DTC present?	Yes	Go to the next step.
1		No	Go to repair completion verification 2.
2	PURPOSE: VERIFY VOLTAGE SUPPLIED TO MICROPHONE Measure the voltage at microphone terminal B (wiring harness-side). Is the voltage approx. 5.5 V?	Yes	Go to Step 5.
2		No	Go to the next step.
3	PURPOSE: VERIFY VOLTAGE WHICH CONNECTIVITY MASTER UNIT (CMU) IS SUPPLYING Measure the voltage at connectivity master unit (CMU) terminal 1F (wiring harness-side). Is the voltage approx. 5.5 V?	Yes	Go to the next step.
3		No	Replace the connectivity master unit (CMU) and perform the repair completion verification 1. (Refer to CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION in service information.)
4	PURPOSE: INSPECT WIRING HARNESS (INCLUDING CONNECTOR/TERMINAL) BETWEEN MICROPHONE AND CONNECTIVITY MASTER UNIT (CMU) FOR MALFUNCTION Inspect the applicable circuit. (See CIRCUIT INSPECTION .) (See CONNECTOR INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
5	PURPOSE: VERIFY VOLTAGE SUPPLIED FROM MICROPHONE CONTROL CIRCUIT Measure the voltage at microphone terminal F (wiring harness-side). Is the voltage approx. 5.43 V?	Yes	Replace the microphone and perform the repair completion verification 1. (Refer to MICROPHONE REMOVAL/INSTALLATION in service information.)
5		No	Go to the next step.
6	PURPOSE: VERIFY VOLTAGE SUPPLIED AT CONTROL CIRCUIT CONTROLLED BY CONNECTIVITY MASTER UNIT (CMU) Measure the voltage at connectivity master unit (CMU) terminal 1G (wiring harness-side). Is the voltage approx. 5.43 V?	Yes	Go to the next step.
6		No	Replace the connectivity master unit (CMU) and perform the repair completion verification 1. (Refer to CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION in service information.)
7	PURPOSE: INSPECT WIRING HARNESS (INCLUDING CONNECTOR/TERMINAL) BETWEEN MICROPHONE AND CONNECTIVITY MASTER UNIT (CMU) FOR MALFUNCTION Inspect the applicable circuit. (See CIRCUIT INSPECTION .) (See CONNECTOR INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location and perform the repair completion verification 1.
Repair completion verification 1	PURPOSE: VERIFY THAT VEHICLE IS REPAIRED Install/connect the part removed/disconnected during the troubleshooting procedure. Clear the DTC recorded in the memory. (See CLEARING DTC .) Replicate the vehicle conditions at the time the DTC was detected using the following procedure. Implement the repeatability verification procedure. (See REPEATABILITY VERIFICATION PROCEDURE .) Perform the DTC inspection for the connectivity master unit (CMU). (See DTC INSPECTION .) Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the connectivity master unit (CMU), then go to the next step. (Refer to CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION in service information.)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	PURPOSE: VERIFY IF OTHER DTCs DISPLAYED Perform the DTC inspection. (See DTC INSPECTION .) Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.