DTC U0184:00 [CONNECTIVITY MASTER UNIT]

id0902n7055000

Description

Communication error with tuner and amp unit (TAU)

Detection condition

•  The connectivity master unit (CMU) cannot receive a CAN signal from the tuner and amp unit (TAU) for 5 s or more.

Fail-safe function

Not applicable

Possible cause

•  Connectivity master unit (CMU) connector or terminal malfunction

•  Tuner and amp unit (TAU) connector or terminal malfunction

•  Connector C-58 connector or terminal malfunction

•  DC-DC converter connector or terminal malfunction

•  Short to power supply in wiring harness between the following terminals:

―  Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA

―  Tuner and amp unit (TAU) terminal 2A—Ground

•  Short to ground in wiring harness between the following terminals:

―  Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB

―  AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T

―  DC-DC converter terminal K—AUDIO1 15 A fuse

•  Short between circuits in the following wiring harness:

―  Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA

―  Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB

•  Open circuit in wiring harness between the following terminals:

―  Tuner and amp unit (TAU) terminal 1AA—Connector C-58

―  Tuner and amp unit (TAU) terminal 1AB—Connector C-58

―  AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T

―  DC-DC converter terminal K—AUDIO1 15 A fuse

―  Tuner and amp unit (TAU) terminal 2A—Ground

―  Connectivity master unit (CMU) terminal 2I—Connector C-58

―  Connectivity master unit (CMU) terminal 2J—Connector C-58

•  AUDIO1 15 A fuse malfunction

•  Tuner and amp unit (TAU) malfunction

•  Connectivity master unit (CMU) malfunction

Description	Communication error with tuner and amp unit (TAU)
Detection condition	• The connectivity master unit (CMU) cannot receive a CAN signal from the tuner and amp unit (TAU) for 5 s or more.
Fail-safe function	Not applicable
Possible cause	• Connectivity master unit (CMU) connector or terminal malfunction • Tuner and amp unit (TAU) connector or terminal malfunction • Connector C-58 connector or terminal malfunction • DC-DC converter connector or terminal malfunction • Short to power supply in wiring harness between the following terminals: ― Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA ― Tuner and amp unit (TAU) terminal 2A—Ground • Short to ground in wiring harness between the following terminals: ― Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB ― AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T ― DC-DC converter terminal K—AUDIO1 15 A fuse • Short between circuits in the following wiring harness: ― Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA ― Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB • Open circuit in wiring harness between the following terminals: ― Tuner and amp unit (TAU) terminal 1AA—Connector C-58 ― Tuner and amp unit (TAU) terminal 1AB—Connector C-58 ― AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T ― DC-DC converter terminal K—AUDIO1 15 A fuse ― Tuner and amp unit (TAU) terminal 2A—Ground ― Connectivity master unit (CMU) terminal 2I—Connector C-58 ― Connectivity master unit (CMU) terminal 2J—Connector C-58 • AUDIO1 15 A fuse malfunction • Tuner and amp unit (TAU) malfunction • Connectivity master unit (CMU) malfunction

Caution

• When disconnecting the connector, verify that there is no looseness, damage, deformation, corrosion, or poor connection of the connector terminals.

Step

Inspection

Action

1

INSPECT FOR POWER SUPPLY-RELATED MALFUNCTION

•  Switch the ignition ON (engine off).

•  Perform the DTC inspection using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 2.2)].)

(See DTC INSPECTION [CONNECTIVITY MASTER UNIT].)

•  Is the power supply or DC-DC converter-related DTC displayed?

Yes

Note

•  It may be affected by power supply-related or DC-DC converter malfunction.

Repair the malfunctioning location according to the applicable DTC troubleshooting.

(See DTC TABLE [PCM (SKYACTIV-D 2.2)].)

(See DTC TABLE [CONNECTIVITY MASTER UNIT].)

No

Go to the next step.

2

INSPECT FOR SHORT TO POWER SUPPLY IN CAN_H SIDE CIRCUIT OF PRIVATE-CAN

•  Measure the voltage between connectivity master unit (CMU) terminal 2I (PRIVATE-CAN CAN_H side) and body ground.

•  Is the voltage B+?

Yes

A short to power supply in CAN_H side circuit of PRIVATE-CAN has occurred.

•  Go to Step 5.

No

Go to the next step.

3

INSPECT FOR SHORT TO GROUND IN CAN_L SIDE CIRCUIT OF PRIVATE-CAN

•  Measure the voltage between connectivity master unit (CMU) terminal 2J (PRIVATE-CAN CAN_L side) and body ground.

•  Is the voltage 0 V?

Yes

A short to ground in CAN_L side circuit of PRIVATE-CAN has occurred.

•  Go to Step 6.

No

Go to the next step.

4

INSPECT BETWEEN PRIVATE-CAN_L AND PRIVATE-CAN_H SIDE CIRCUITS FOR SHORT BETWEEN CIRCUITS

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Measure the resistance between connectivity master unit (CMU) 2I and 2J terminals (wiring harness side).

•  Is the resistance approx. 60 ohms?

Yes

Go to the next step. (PRIVATE-CAN is normal.)

No

If the resistance is 0 ohm:

•  A short between circuits has occurred in PRIVATE-CAN.

―  Go to Step 7.

If the resistance is 120 ohms:

•  An open circuit in the PRIVATE-CAN has occurred.

―  Go to Step 8.

5

INSPECT WIRING HARNESS FOR SHORT TO POWER SUPPLY

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the following connectors:

―  Connectivity master unit (CMU)

―  Tuner and amp unit (TAU)

•  Reconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

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

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

―  Connectivity master unit (CMU) terminal 2I

―  Tuner and amp unit (TAU) terminal 1AA

•  Is the voltage 0 V?

Yes

Go to Step 11.

No

Refer to the wiring diagram and verify if there is a common connector between the following terminals.

•  Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA

•  Tuner and amp unit (TAU) terminal 2A—Ground

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

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

Go to Step 12.

6

INSPECT WIRING HARNESS FOR SHORT TO GROUND

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the following connectors:

―  Connectivity master unit (CMU)

―  Tuner and amp unit (TAU)

―  DC-DC converter

•  Inspect for continuity between the following terminals (wiring harness side) and body ground.

―  Connectivity master unit (CMU) terminal 2J

―  Tuner and amp unit (TAU) terminal 2T

―  Tuner and amp unit (TAU) terminal 1AB

•  Is there continuity?

Yes

Refer to the wiring diagram and verify if there is a common connector between the following terminals.

•  Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB

•  AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T

•  DC-DC converter terminal K—AUDIO1 15 A fuse

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

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

Go to Step 12.

No

Go to Step 11.

7

INSPECT WIRING HARNESS FOR SHORT BETWEEN CIRCUITS

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the following connectors:

―  Connectivity master unit (CMU)

―  Tuner and amp unit (TAU)

•  Inspect for continuity between the following terminals (wiring harness side).

―  Connectivity master unit (CMU) terminals 2I and 2J

―  Tuner and amp unit (TAU) terminals 1AA and 1AB

•  Is there continuity?

Yes

Refer to the wiring diagram and verify if there is a common connector between the following terminals.

•  Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA

•  Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short between circuits to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

•  Repair or replace the wiring harness which has shorted between circuits.

Go to Step 12.

No

Go to Step 11.

8

INSPECT WIRING HARNESS FOR OPEN CIRCUIT

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the following connectors:

―  Connectivity master unit (CMU)

―  Tuner and amp unit (TAU)

―  Connector C-58

•  Inspect the for continuity between the following terminals (wiring harness side).

―  Tuner and amp unit (TAU) terminal 1AA—Connector C-58

―  Tuner and amp unit (TAU) terminal 1AB—Connector C-58

―  Connectivity master unit (CMU) terminal 2I—Connector C-58

―  Connectivity master unit (CMU) terminal 2J—Connector C-58

•  Is there continuity?

Yes

Go to Step 11.

No

Refer to the wiring diagram and verify if there is a common connector between the following terminals.

•  Tuner and amp unit (TAU) terminal 1AA—Connector C-58

•  Tuner and amp unit (TAU) terminal 1AB—Connector C-58

•  Connectivity master unit (CMU) terminal 2I—Connector C-58

•  Connectivity master unit (CMU) terminal 2J—Connector C-58

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

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

Go to Step 12.

9

INSPECT TUNER AND AMP UNIT (TAU) RELATED-WIRING HARNESS FOR OPEN CIRCUIT

•  Switch the ignition off.

•  Disconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

•  Disconnect the tuner and amp unit (TAU) connector.

•  Inspect for continuity between tuner and amp unit (TAU) terminal 2A (wiring harness side) and ground.

•  Is there continuity?

Yes

Go to the next step.

No

Repair or replace the wiring harness which has an open circuit, then go to Step 12.

10

VERIFY TUNER AND AMP UNIT (TAU) POWER SUPPLY VOLTAGE

•  Verify that the tuner and amp unit (TAU) connector is disconnected.

•  Reconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

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

•  Measure the voltage at tuner and amp unit (TAU) terminal 2T (wiring harness side).

•  Is the voltage 10 V or more?

Yes

Replace the tuner and amp unit (TAU), then go to Step 12.

(See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)

No

Inspect the AUDIO1 15 A fuse.

•  If the fuse is blown:

―  Refer to the wiring diagram and verify if there is a common connector between AUDIO1 15 A fuse and tuner and amp unit (TAU) terminal 2T.

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

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

•  Replace the fuse.

•  If the fuse is damaged:

―  Replace the fuse.

•  If the fuse is normal:

―  Refer to the wiring diagram and verify if there is a common connector between DC-DC converter terminal K and tuner and amp unit (TAU) terminal 2T.

If there is a common connector:

•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location.

•  Repair or replace the malfunctioning location.

If there is no common connector:

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

Go to Step 12.

11

PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS TUNER AND AMP UNIT (TAU)

•  Always reconnect all disconnected connectors.

•  Reconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL 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 12 s or more.

•  Perform the DTC inspection for the connectivity master unit (CMU) using the M-MDS.
(See DTC INSPECTION [CONNECTIVITY MASTER UNIT].)

•  Is the same Pending DTC present?

Yes

Replace the tuner and amp unit (TAU), then go to the next step.

(See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)

No

Go to Step 13.

12

VERIFY THAT REPAIRS HAVE BEEN COMPLETED

•  Always reconnect all disconnected connectors.

•  Reconnect the negative battery terminal.
(See NEGATIVE BATTERY TERMINAL 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 12 s or more.

•  Perform the DTC inspection for the connectivity master unit (CMU) using the M-MDS.
(See DTC INSPECTION [CONNECTIVITY MASTER UNIT].)

•  Is the same Pending DTC present?

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.

13

VERIFY OTHER DTCs

•  Are any other DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

(See DTC TABLE [CONNECTIVITY MASTER UNIT].)

No

DTC troubleshooting completed.

Step	Inspection		Action
1	INSPECT FOR POWER SUPPLY-RELATED MALFUNCTION • Switch the ignition ON (engine off). • Perform the DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-D 2.2)].) (See DTC INSPECTION [CONNECTIVITY MASTER UNIT].) • Is the power supply or DC-DC converter-related DTC displayed?	Yes	Note • It may be affected by power supply-related or DC-DC converter malfunction. Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-D 2.2)].) (See DTC TABLE [CONNECTIVITY MASTER UNIT].)
1		No	Go to the next step.
2	INSPECT FOR SHORT TO POWER SUPPLY IN CAN_H SIDE CIRCUIT OF PRIVATE-CAN • Measure the voltage between connectivity master unit (CMU) terminal 2I (PRIVATE-CAN CAN_H side) and body ground. • Is the voltage B+?	Yes	A short to power supply in CAN_H side circuit of PRIVATE-CAN has occurred. • Go to Step 5.
2		No	Go to the next step.
3	INSPECT FOR SHORT TO GROUND IN CAN_L SIDE CIRCUIT OF PRIVATE-CAN • Measure the voltage between connectivity master unit (CMU) terminal 2J (PRIVATE-CAN CAN_L side) and body ground. • Is the voltage 0 V?	Yes	A short to ground in CAN_L side circuit of PRIVATE-CAN has occurred. • Go to Step 6.
3		No	Go to the next step.
4	INSPECT BETWEEN PRIVATE-CAN_L AND PRIVATE-CAN_H SIDE CIRCUITS FOR SHORT BETWEEN CIRCUITS • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Measure the resistance between connectivity master unit (CMU) 2I and 2J terminals (wiring harness side). • Is the resistance approx. 60 ohms?	Yes	Go to the next step. (PRIVATE-CAN is normal.)
4		No	If the resistance is 0 ohm: • A short between circuits has occurred in PRIVATE-CAN. ― Go to Step 7. If the resistance is 120 ohms: • An open circuit in the PRIVATE-CAN has occurred. ― Go to Step 8.
5	INSPECT WIRING HARNESS FOR SHORT TO POWER SUPPLY • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the following connectors: ― Connectivity master unit (CMU) ― Tuner and amp unit (TAU) • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminals (wiring harness side). ― Connectivity master unit (CMU) terminal 2I ― Tuner and amp unit (TAU) terminal 1AA • Is the voltage 0 V?	Yes	Go to Step 11.
5		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. • Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA • Tuner and amp unit (TAU) terminal 2A—Ground If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which is shorted to the power supply. Go to Step 12.
6	INSPECT WIRING HARNESS FOR SHORT TO GROUND • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the following connectors: ― Connectivity master unit (CMU) ― Tuner and amp unit (TAU) ― DC-DC converter • Inspect for continuity between the following terminals (wiring harness side) and body ground. ― Connectivity master unit (CMU) terminal 2J ― Tuner and amp unit (TAU) terminal 2T ― Tuner and amp unit (TAU) terminal 1AB • Is there continuity?	Yes	Refer to the wiring diagram and verify if there is a common connector between the following terminals. • Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB • AUDIO1 15 A fuse—Tuner and amp unit (TAU) terminal 2T • DC-DC converter terminal K—AUDIO1 15 A fuse If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which is shorted to ground. Go to Step 12.
6		No	Go to Step 11.
7	INSPECT WIRING HARNESS FOR SHORT BETWEEN CIRCUITS • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the following connectors: ― Connectivity master unit (CMU) ― Tuner and amp unit (TAU) • Inspect for continuity between the following terminals (wiring harness side). ― Connectivity master unit (CMU) terminals 2I and 2J ― Tuner and amp unit (TAU) terminals 1AA and 1AB • Is there continuity?	Yes	Refer to the wiring diagram and verify if there is a common connector between the following terminals. • Connectivity master unit (CMU) terminal 2I—Tuner and amp unit (TAU) terminal 1AA • Connectivity master unit (CMU) terminal 2J—Tuner and amp unit (TAU) terminal 1AB If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short between circuits to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which has shorted between circuits. Go to Step 12.
7		No	Go to Step 11.
8	INSPECT WIRING HARNESS FOR OPEN CIRCUIT • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the following connectors: ― Connectivity master unit (CMU) ― Tuner and amp unit (TAU) ― Connector C-58 • Inspect the for continuity between the following terminals (wiring harness side). ― Tuner and amp unit (TAU) terminal 1AA—Connector C-58 ― Tuner and amp unit (TAU) terminal 1AB—Connector C-58 ― Connectivity master unit (CMU) terminal 2I—Connector C-58 ― Connectivity master unit (CMU) terminal 2J—Connector C-58 • Is there continuity?	Yes	Go to Step 11.
8		No	Refer to the wiring diagram and verify if there is a common connector between the following terminals. • Tuner and amp unit (TAU) terminal 1AA—Connector C-58 • Tuner and amp unit (TAU) terminal 1AB—Connector C-58 • Connectivity master unit (CMU) terminal 2I—Connector C-58 • Connectivity master unit (CMU) terminal 2J—Connector C-58 If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to Step 12.
9	INSPECT TUNER AND AMP UNIT (TAU) RELATED-WIRING HARNESS FOR OPEN CIRCUIT • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the tuner and amp unit (TAU) connector. • Inspect for continuity between tuner and amp unit (TAU) terminal 2A (wiring harness side) and ground. • Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace the wiring harness which has an open circuit, then go to Step 12.
10	VERIFY TUNER AND AMP UNIT (TAU) POWER SUPPLY VOLTAGE • Verify that the tuner and amp unit (TAU) connector is disconnected. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at tuner and amp unit (TAU) terminal 2T (wiring harness side). • Is the voltage 10 V or more?	Yes	Replace the tuner and amp unit (TAU), then go to Step 12. (See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)
10		No	Inspect the AUDIO1 15 A fuse. • If the fuse is blown: ― Refer to the wiring diagram and verify if there is a common connector between AUDIO1 15 A fuse and tuner and amp unit (TAU) terminal 2T. If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which is shorted to ground. • Replace the fuse. • If the fuse is damaged: ― Replace the fuse. • If the fuse is normal: ― Refer to the wiring diagram and verify if there is a common connector between DC-DC converter terminal K and tuner and amp unit (TAU) terminal 2T. If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to Step 12.
11	PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS TUNER AND AMP UNIT (TAU) • Always reconnect all disconnected connectors. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL 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 12 s or more. • Perform the DTC inspection for the connectivity master unit (CMU) using the M-MDS. (See DTC INSPECTION [CONNECTIVITY MASTER UNIT].) • Is the same Pending DTC present?	Yes	Replace the tuner and amp unit (TAU), then go to the next step. (See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)
11		No	Go to Step 13.
12	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Always reconnect all disconnected connectors. • Reconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL 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 12 s or more. • Perform the DTC inspection for the connectivity master unit (CMU) using the M-MDS. (See DTC INSPECTION [CONNECTIVITY MASTER UNIT].) • Is the same Pending DTC present?	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.
12		No	Go to the next step.
13	VERIFY OTHER DTCs • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [CONNECTIVITY MASTER UNIT].)
13	VERIFY OTHER DTCs • Are any other DTCs displayed?	No	DTC troubleshooting completed.