Description

Microphone circuit malfunction

Detection condition

• The connectivity master unit (CMU) detected microphone circuit voltage of less than 7.7 V or more than 8.6 V with the ignition switched ON (engine off or on).

Fail-safe

Not applicable

Possible cause

• Microphone connector or terminal malfunction

• Connectivity master unit (CMU) connector or terminal malfunction

• Short to ground in wiring harness between connectivity master unit (CMU) terminal 1Q and microphone terminal C

• Short to power supply in wiring harness between connectivity master unit (CMU) terminal 1Q and microphone terminal C

• Open circuit in wiring harness between connectivity master unit (CMU) terminal 1Q and microphone terminal C

• Microphone malfunction

• Connectivity master unit (CMU) malfunction

Step

Inspection

Action

1

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Disconnect the microphone connector.

• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

• Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, then go to Step 7.

2

• Disconnect the connectivity master unit (CMU) connector.

• Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.

• Is the connector normal?

Yes

Go to the next step.

No

Repair or replace the connector, then go to Step 7.

3

• Verify that the microphone and connectivity master unit (CMU) connectors are disconnected.

• Inspect for continuity between connectivity master unit (CMU) terminal 1Q (wiring harness-side) and body ground.

• Is there continuity?

Yes

Refer to the wiring diagram and verify if there is a common connector between connectivity master unit (CMU) terminal 1Q and microphone terminal C.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

Go to Step 7.

No

Go to the next step.

4

• Verify that the microphone and connectivity master unit (CMU) connectors are disconnected.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Switch the ignition ON (engine off or on).

• Measure the voltage at microphone terminal C (wiring harness-side).

• Is the voltage 0 V?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify if there is a common connector between connectivity master unit (CMU) terminal 1Q and microphone terminal C.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 7.

5

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Verify that the microphone and connectivity master unit (CMU) connectors are disconnected.

• Inspect the wiring harness for continuity between connectivity master unit (CMU) terminal 1Q (wiring harness-side) and microphone terminal C (wiring harness-side).

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify if there is a common connector between connectivity master unit (CMU) terminal 1Q and microphone terminal C.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 7.

6

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Clear the DTC for the connectivity master unit (CMU) using the M-MDS.

  (See CLEARING DTC [CONNECTIVITY MASTER UNIT].)

• Switch the ignition ON (engine off or on) and wait for 7 s or more.

• Retrieve the connectivity master unit (CMU) DTCs using the M-MDS.

  (See DTC INSPECTION [CONNECTIVITY MASTER UNIT].)

• Is the same DTC displayed?

Yes

Replace the microphone, then go to the next step.

(See MICROPHONE REMOVAL/INSTALLATION.)

No

Go to Step 8.

7

• Always reconnect all disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION.)

• Clear the DTC for the connectivity master unit (CMU) using the M-MDS.

  (See CLEARING DTC [CONNECTIVITY MASTER UNIT].)

• Switch the ignition ON (engine off or on) and wait for 7 s or more.

• Retrieve the connectivity master unit (CMU) DTCs using the M-MDS.

  (See DTC INSPECTION [CONNECTIVITY MASTER UNIT].)

• Is the same DTC displayed?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the connectivity master unit (CMU).

  (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

8

• Are any other DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [CONNECTIVITY MASTER UNIT].)

No

DTC troubleshooting completed.