Mitsubishi Motors Service Manual

2018 / ECLIPSE CROSS / EC - Workshop Manual

13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. B1301 DC/DC CONVERTER (ENTERTAINMENT SYSTEM) PERFORMANCE

Code No. B1301: DC/DC Converter (Entertainment System) Performance

OPERATION

At the auto start, the engine-ECU connector terminal DCCT sends increasing voltage request signal to the DC/DC converter (entertainment system) connector terminal DCCT.
If the increasing voltage control system is abnormal, the DC/DC converter (entertainment system) connector terminal DCCA should send the diagnostic signal to the engine-ECU connector terminal DCDT.

FUNCTION

The engine-ECU checks whether the increasing voltage control system is normal.

TROUBLE JUDGEMENT

Check Conditions

2 seconds later after the ignition switch has been in ON position.
Battery voltage is 6.3 V or more.

Judgement Criterion

For 2 seconds, the duty signal (failure signal) is received in a row.

FAIL-SAFE AND BACKUP FUNCTION

None.

PROBABLE CAUSES

Connection with accessories having rated output current large enough to possibly cause overloads (overcurrents).
Modified circuit
Failed battery
Open/short circuit or harness damage in DC/DC converter (entertainment system) circuit or loose connector contact
Failed DC/DC converter (entertainment system)
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the vehicle status for use

Ask the user whether he or she connects the vehicle with accessories having the rated output current large enough to possibly cause overloads (overcurrents) or not. Or ask the user whether he or she modifies the circuit or not.

Does the user connect the vehicle with accessories having the large rated output current? Or does the user modify the circuit?

Turn OFF the accessories or remove them. Then go to Step 2.

Go to Step 2.

STEP 2. M.U.T.-IIISE data list

note	Before checking the data list, carry out the operation, Step 1-3, to reset the diagnosis information of the DC/DC converter (entertainment system). If the operation is swiftly carried out, the diagnosis code can be set. Slowly carry out the operation, Step 1-3.

Turn the ignition switch to "ACC" position.
Turn the ignition switch to "LOCK" (OFF) position.
Repeat Steps 1-2.
Turn the ignition switch to "ON" position and check the data list after having passed for more than 60 seconds.

Item 190: DC-DC OUT (Input)

OK: ON

Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

Go to Step 3.

STEP 3. Check the operation of the accessories

Ignition switch: ACC

OK: Radio and CD player operates or multivision display operates

Is the check result normal?

Go to Step 4.

NO <Vehicles with radio and CD player> : Perform the troubleshooting of the radio and CD player (Refer to GROUP 54A - Radio and CD Player - Symptom Chart

NO <Vehicles with MMCS> : Perform the troubleshooting of the multivision display (Refer to GROUP 54A - Mitsubishi Multi Communication System (MMCS) - Symptom Chart

STEP 4. Check the DC/DC converter (entertainment system) power supply circuit

Check the DC/DC converter (entertainment system) power supply circuit (Refer to GROUP 54A - DC/DC Converter - Symptom Procedures - Check the DC/DC Converter Power Supply Circuit ).

Is the check result normal?

Go to Step 5.

Repair the circuit according to the troubleshooting and go to Step 5.

STEP 5. Perform voltage measurement at engine-ECU connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal DCCT and body earth.

OK: System voltage

Is the check result normal?

Go to Step 7.

Go to Step 6.

STEP 6. Check of short to earth, and open circuit in DCCT line between DC/DC converter (entertainment system) connector and engine-ECU connector.

Is the check result normal?

Replace the DC/DC converter (entertainment system).

Repair the connector(s) or wiring harness.

STEP 7. Perform voltage measurement at DC/DC converter (entertainment system) connector by back probing.

Measure DC/DC converter (entertainment system) terminal voltage.
Ignition switch: ON
Voltage between terminal DCCT and body earth.

OK: 1 V or less

Is the check result normal?

Go to Step 9.

Go to Step 8.

STEP 8. M.U.T.-IIISE diagnosis code

Reconfirmation of the diagnosis code.

Is the diagnosis code set?

Replace the engine-ECU.

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

STEP 9. Perform voltage measurement at DC/DC converter (entertainment system) connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal DCDT and body earth.

OK: System voltage

Is the check result normal?

Go to Step 10.

Repair the connector(s), or check and repair of short to earth in DCCA to DCDT line between DC/DC converter (entertainment system) connector and engine-ECU connector.

STEP 10. Check of harness damage in DCCT line between engine-ECU connector and DC/DC converter (entertainment system) connector.

Is the check result normal?

Go to Step 11.

Repair the connector(s) or wiring harness.

STEP 11. Perform voltage measurement at DC/DC converter (entertainment system) connector by back probing.

Measure DC/DC converter (entertainment system) terminal voltage.
Voltage between terminal OUT1 and body earth at auto start.
Voltage between terminal OUT2 and body earth at auto start.
Check the difference among the measured voltage of the terminal OUT1 and the measured voltage of the terminal OUT2.

OK: Under 0.3 V

Is the check result normal?

Go to Step 12.

Replace the DC/DC converter (entertainment system).

STEP 12. M.U.T.-IIISE diagnosis code

note	Before rechecking the diagnosis code is set, carry out the operation, Step 1-3, to reset the diagnosis information of the DC/DC converter (entertainment system). If the operation is swiftly carried out, the diagnosis code can be set. Slowly carry out the operation, Step 1-3.

Turn the ignition switch to "ACC" position.
Turn the ignition switch to "LOCK" (OFF) position.
Repeat Steps 1-2.
Confirm again whether the diagnosis code is set.

Is the diagnosis code set?

Replace the DC/DC converter (entertainment system). Then go to Step 13 .

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions

STEP 13. M.U.T.-IIISE diagnosis code

Reconfirmation of the diagnosis code.

Is the diagnosis code set?

Replace the engine-ECU.

Check end.