Description

Voltage decrease input from battery

Detection condition

With the ignition switched to ACC or ON, the audio unit detects voltage from the battery of 10 V or less for 30 s or more.

Fail-safe function

Not applicable

Possible cause

• Battery malfunction

• Generator malfunction

• Audio unit connector or terminal malfunction

• Audio unit power supply circuit malfunction

• Short to ground in the wiring harness between audio unit terminal 1B and battery (+) terminal.

• Short to ground in wiring harness between audio unit terminal 1R and ACC RELAY

• AUDIO1 15 A fuse malfunction

• AUDIO2 7.5 A fuse malfunction

• CABIN. +B 50 A fuse malfunction

• MAIN 200 A fuse malfunction

• Open circuit in wiring harness between audio unit terminal 1B and battery (+) terminal

• Open circuit in wiring harness between audio unit terminal 1R and ACC RELAY

• Audio unit malfunction

Step

Inspection

Action

1

• Perform the DTC inspection for the PCM using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• Is the DTC displayed?

Yes

Repair the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [SKYACTIV-G 2.5].)

No

Go to the next step.

2

• Inspect the battery.

  (See BATTERY INSPECTION [SKYACTIV-G 2.5].)

• Is there any malfunctioning part?

Yes

Recharge or replace the battery, then go to Step 8.

(See BATTERY RECHARGING [SKYACTIV-G 2.5].)

(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.5].)

No

Go to the next step.

3

• Inspect the generator.

  (See GENERATOR INSPECTION [i-ELOOP].)

  (See GENERATOR INSPECTION [SKYACTIV-G 2.5 (WITHOUT i-ELOOP)].)

• Is there any malfunctioning part?

Yes

Replace the generator, then go to Step 8.

(See GENERATOR REMOVAL/INSTALLATION [i-ELOOP].)

(See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5 (WITHOUT i-ELOOP)].)

No

Go to the next step.

4

INSPECT AUDIO UNIT CONNECTOR CONDITION

• Switch the ignition off (LOCK).

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Disconnect the audio unit connector.

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

• Is there any malfunctioning part?

Yes

Repair or replace the connector, then go to Step 8.

No

Go to the next step.

5

INSPECT POWER SUPPLY CIRCUIT OF AUDIO UNIT FOR MALFUNCTION

• Verify that the audio unit connector is disconnected.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Switch the ignition to ACC (engine off).

• Measure the voltage at the following terminals (vehicle wiring harness side).

• Audio unit terminal 1B

• Audio unit terminal 1R

• Is the voltage B+?

Yes

Go to Step 8.

No

• Terminal 1B voltage is not B+

• Go to Step 7.

• Terminal 1R voltage is not B+

• Go to the next step.

6

INSPECT AUDIO UNIT POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND

• Switch the ignition off (LOCK).

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Inspect the AUDIO2 7.5 A fuse.

• Is there any malfunctioning part?

Yes

• If a fuse is burnt out:

• Repair or replace the wiring harness which is shorted to ground.

• Replace the malfunctioning fuse.

• If a fuse is damaged:

• Replace the malfunctioning fuse.

Go to Step 8.

No

Repair or replace the wiring harness for a possible open circuit, then go to Step 8.

7

INSPECT AUDIO UNIT POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND

• Switch the ignition off (LOCK).

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Inspect the CABIN. +B 50 A fuse, AUDIO1 15A fuse and MAIN 200 A fuse.

• Is there any malfunctioning part?

Yes

• If a fuse is burnt out:

• Repair or replace the wiring harness which is shorted to ground.

• Replace the malfunctioning fuse.

• If a fuse is damaged:

• Replace the malfunctioning fuse.

Go to the next step.

No

Repair or replace the wiring harness for a possible open circuit, then go to the next step.

8

VERIFY THAT REPAIRS HAVE BEEN COMPLETED

• Switch the ignition off (LOCK).

• Reconnect all the disconnected connectors.

• Connect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Clear the audio unit DTCs.

  (See CLEARING DTC [AUDIO].)

• Perform the audio unit DTC inspection.

  (See DTC INSPECTION [AUDIO].)

• Is the same DTC displayed?

Yes

Return to Step 1 and inspect for other possible causes.

If the malfunction recurs, replace the audio unit, then go to the next step.

(See AUDIO UNIT REMOVAL/INSTALLATION.)

No

Go to the next step.

9

VERIFY IF OTHER DTCs DISPLAYED

• Verify if other DTCs are displayed.

• Are any other DTCs displayed?

Yes

Repair the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [AUDIO].)

No

DTC troubleshooting completed.