DTC B1238:16 [CONNECTIVITY MASTER UNIT]

id0902n7104900


Without i-stop System

Description

Tuner and amp unit (TAU) low power supply voltage input
Detection condition
•  Connectivity master unit (CMU) detects power supply circuit voltage for tuner and amp unit (TAU) of less than 10 V for 10 s or more with the ignition switched ON (engine off or on).
Fail-safe
Not applicable
Possible cause
•  DTCs are stored in the PCM.
•  Battery malfunction
•  Generator malfunction
•  Tuner and amp unit (TAU) connector or terminal malfunction
•  Tuner and amp unit (TAU) power supply circuit malfunction
?  Short to ground in wiring harness between AUDIO 40 A fuse and tuner and amp unit (TAU) terminal 2T
?  AUDIO3 15 A fuse malfunction
?  AUDIO1 25 A fuse malfunction
?  AUDIO 40 A fuse malfunction
?  Open circuit in wiring harness between battery positive terminal and tuner and amp unit (TAU) terminal 2T
•  Tuner and amp unit (TAU) malfunction

Diagnostic Procedure

Step

Inspection

Action
1
VERIFY PCM DTCs
•  Retrieve the PCM DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
Go to the next step.
2
INSPECT BATTERY
•  Inspect the battery.
•  Is the battery normal?
Yes
Go to the next step.
No
Recharge or replace the battery, then go to Step 6.
(See BATTERY RECHARGING.)
(See BATTERY REMOVAL/INSTALLATION.)
3
INSPECT GENERATOR
•  Inspect the generator.
•  Is the generator normal?
Yes
Go to the next step.
No
Replace the generator, then go to Step 6.
(See GENERATOR REMOVAL/INSTALLATION [WITHOUT i-ELOOP (SKYACTIV-G 2.5T)].)
4
INSPECT TUNER AND AMP UNIT (TAU) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the tuner and amp unit (TAU) 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 6.
5
VERIFY TUNER AND AMP UNIT (TAU) POWER SUPPLY VOLTAGE
•  Verify that the tuner and amp unit (TAU) connector is disconnected.
•  Connect the negative battery terminal.
•  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
Go to the next step.
No
Inspect the AUDIO3 15 A fuse, AUDIO1 25 A fuse, and AUDIO 40 A fuse.
•  Any fuse is blown:
?  Refer to the wiring diagram and verify if there is a common connector between AUDIO 40 A fuse and tuner and amp unit (TAU) terminal 2T.
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 location.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  Any fuse is damaged:
?  Replace the fuse.
•  All fuses are normal:
?  Refer to the wiring diagram and verify if there is a common connector between battery positive terminal and tuner and amp unit (TAU) terminal 2T.
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 location.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to the next step.
6
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Clear the DTC for the connectivity master unit (CMU) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 17 s or more.
•  Retrieve the connectivity master unit (CMU) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the tuner and amp unit (TAU).
Go to the next step.
No
Go to the next step.
7
VERIFY IF OTHER DTCs DISPLAYED
•  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.


Without i-ELOOP, with i-stop System

Description

Tuner and amp unit (TAU) low power supply voltage input
Detection condition
•  Connectivity master unit (CMU) detects power supply circuit voltage for tuner and amp unit (TAU) of less than 10 V for 10 s or more with the ignition switched ON (engine off or on).
Fail-safe
Not applicable
Possible cause
•  DTCs are stored in the PCM.
•  Battery malfunction
•  Generator malfunction
•  Tuner and amp unit (TAU) connector or terminal malfunction
•  Tuner and amp unit (TAU) power supply circuit malfunction
?  Short to ground in wiring harness between AUDIO1 25 A fuse and tuner and amp unit (TAU) terminal 2T
?  AUDIO3 15 A fuse malfunction
?  AUDIO1 25 A fuse malfunction
?  Open circuit in wiring harness DC-DC converter terminal K and tuner and amp unit (TAU) terminal 2T
•  DC-DC converter connector or terminal malfunction
•  DC-DC converter malfunction
•  Tuner and amp unit (TAU) malfunction

Diagnostic Procedure

Step

Inspection

Action
1
VERIFY PCM DTCs
•  Retrieve the PCM DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
Go to the next step.
2
INSPECT BATTERY
•  Inspect the battery.
•  Is the battery normal?
Yes
Go to the next step.
No
Recharge or replace the battery, then go to Step 8.
(See BATTERY RECHARGING.)
(See BATTERY REMOVAL/INSTALLATION.)
3
INSPECT GENERATOR
•  Inspect the generator.
•  Is the generator normal?
Yes
Go to the next step.
No
Replace the generator, then go to Step 8.
(See GENERATOR REMOVAL/INSTALLATION [WITH i-ELOOP (SKYACTIV-G 2.5T)].)
4
INSPECT TUNER AND AMP UNIT (TAU) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the tuner and amp unit (TAU) 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 8.
5
VERIFY TUNER AND AMP UNIT (TAU) POWER SUPPLY VOLTAGE
•  Verify that the tuner and amp unit (TAU) connector is disconnected.
•  Connect the negative battery terminal.
•  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
Go to the next step.
No
Inspect the AUDIO3 15 A fuse and AUDIO1 25 A fuse.
•  Any fuse is blown:
?  Refer to the wiring diagram and verify if there is a common connector between AUDIO1 25 A fuse and tuner and amp unit (TAU) terminal 2T.
If there is a common connector:
•  Determine the malfunctioning location by inspecting the common connector and terminals for corrosion, damage, or disconnection and by inspecting the DC-DC converter terminal K-related wiring harness for a short to ground.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  Any fuse is damaged:
?  Replace the fuse.
•  All fuses are 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:
•  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 location.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
6
INSPECT DC-DC CONVERTER CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the DC-DC converter 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 8.
7
INSPECT DC-DC CONVERTER
•  Inspect the DC-DC converter.
•  Is there any malfunctioning part?
Yes
Repair or replace the DC-DC converter and go to the next step.
(See DC-DC CONVERTER REMOVAL/INSTALLATION [WITHOUT i-ELOOP (SKYACTIV-G 2.5T)].)
No
Go to the next step.
8
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Clear the DTC for the connectivity master unit (CMU) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 17 s or more.
•  Retrieve the connectivity master unit (CMU) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the tuner and amp unit (TAU).
Go to the next step.
No
Go to the next step.
9
VERIFY IF OTHER DTCs DISPLAYED
•  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.


With i-ELOOP, with i-stop System

Description

Tuner and amp unit (TAU) low power supply voltage input
Detection condition
•  Connectivity master unit (CMU) detects power supply circuit voltage for tuner and amp unit (TAU) of less than 10 V for 10 s or more with the ignition switched ON (engine off or on).
Fail-safe
Not applicable
Possible cause
•  DTCs are stored in the PCM.
•  DTCs are stored in the DC-DC converter (i-ELOOP).
?  DC-DC converter (i-ELOOP) connector or terminal malfunction
?  DC-DC converter (i-ELOOP) malfunction
•  Battery malfunction
•  Generator malfunction
•  Tuner and amp unit (TAU) connector or terminal malfunction
•  Tuner and amp unit (TAU) power supply circuit malfunction
?  Short to ground in wiring harness between AUDIO1 25 A fuse and tuner and amp unit (TAU) terminal 2T
?  AUDIO3 15 A fuse malfunction
?  AUDIO1 25 A fuse malfunction
?  Open circuit in wiring harness DC-DC converter (i-ELOOP) terminal 4A and tuner and amp unit (TAU) terminal 2T
•  Tuner and amp unit (TAU) malfunction

Diagnostic Procedure

Step

Inspection

Action
1
VERIFY PCM DTCs
•  Retrieve the PCM DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
No
Go to the next step.
2
VERIFY DC-DC CONVERTER (i-ELOOP) DTCs
•  Retrieve the DC-DC converter (i-ELOOP) DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [i-ELOOP].)
No
Go to the next step.
3
INSPECT BATTERY
•  Inspect the battery.
•  Is the battery normal?
Yes
Go to the next step.
No
Recharge or replace the battery, then go to Step 7.
(See BATTERY RECHARGING.)
(See BATTERY REMOVAL/INSTALLATION.)
4
INSPECT GENERATOR
•  Inspect the generator.
•  Is the generator normal?
Yes
Go to the next step.
No
Replace the generator, then go to Step 7.
(See GENERATOR REMOVAL/INSTALLATION [WITH i-ELOOP (SKYACTIV-G 2.5T)].)
5
INSPECT TUNER AND AMP UNIT (TAU) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the tuner and amp unit (TAU) 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.
6
VERIFY TUNER AND AMP UNIT (TAU) POWER SUPPLY VOLTAGE
•  Verify that the tuner and amp unit (TAU) connector is disconnected.
•  Connect the negative battery terminal.
•  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
Go to the next step.
No
Disconnect the service plug.
(See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].)
Inspect the AUDIO3 15 A fuse and AUDIO1 25 A fuse.
•  Any fuse is blown:
?  Refer to the wiring diagram and verify if there is a common connector between AUDIO1 25 A fuse and tuner and amp unit (TAU) terminal 2T.
If there is a common connector:
•  Determine the malfunctioning location by inspecting the common connector and terminals for corrosion, damage, or disconnection and by inspecting the DC-DC converter (i-ELOOP) terminal 4A-related wiring harness for a short to ground.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
•  Replace the fuse.
•  Any fuse is damaged:
?  Replace the fuse.
•  All fuses are normal:
?  Refer to the wiring diagram and verify if there is a common connector between DC-DC converter (i-ELOOP) terminal 4A and tuner and amp unit (TAU) terminal 2T.
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 location.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Connect the service plug, then go to the next step.
(See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].)
7
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Clear the DTC for the connectivity master unit (CMU) using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 17 s or more.
•  Retrieve the connectivity master unit (CMU) DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the tuner and amp unit (TAU).
Go to the next step.
No
Go to the next step.
8
VERIFY IF OTHER DTCs DISPLAYED
•  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.