DTC U0401:00 [PCM (SKYACTIV-X)]

System malfunction location	Error signal received from PCM
Detection condition	• The PCM detects that the integrated starter generator (ISG) stores the DTC U0401:00.
Fail-safe	• Controls the voltage generated by the integrated starter generator (ISG) at 22.5 V.
Possible cause	• DTCs are stored in the integrated starter generator (ISG). Note • If the integrated starter generator (ISG) stores a DTC, the PCM stores the same DTC or similar. • If the PCM stores a DTC even though the integrated starter generator (ISG) does not store a DTC, clear the DTC as it was for a past malfunction, and then complete the repair. • PCM malfunction • Integrated starter generator (ISG) malfunction
System wiring diagram	• Not applicable
Connector diagram	• Not applicable

System malfunction location

Error signal received from PCM

Detection condition

• The PCM detects that the integrated starter generator (ISG) stores the DTC U0401:00.

Fail-safe

• Controls the voltage generated by the integrated starter generator (ISG) at 22.5 V.

Possible cause

• DTCs are stored in the integrated starter generator (ISG).

Note

• If the integrated starter generator (ISG) stores a DTC, the PCM stores the same DTC or similar.

• If the PCM stores a DTC even though the integrated starter generator (ISG) does not store a DTC, clear the DTC as it was for a past malfunction, and then complete the repair.

• PCM malfunction

• Integrated starter generator (ISG) malfunction

System wiring diagram

• Not applicable

Connector diagram

• Not applicable

Step	Inspection	Results	Action
1	RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION • Record the freeze frame data/snapshot data. Note • Recording can be facilitated using the screen capture function of the PC.	—	Go to the next step.
2	VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY • Verify related Service Bulletins, on-line repair information, or Service Information availability. • Is any related Information available?	Yes	Perform repair or diagnosis according to the available information. • If the vehicle is not repaired, go to the next step.
No	Go to the next step.
3	INSPECT FOR OTHER RELATED DTCs • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-X)].)
No	Go to the next step.
4	INSPECT PCM FOR MALFUNCTION DEPENDING ON REPEATABILITY • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
No	Perform the repair completion verification 2.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the integrated starter generator (ISG), then go to the next step. (See INTEGRATED STARTER GENERATOR (ISG) REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)
No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTCs DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
No	DTC troubleshooting completed.

Step

Inspection

Results

Action

RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION

• Record the freeze frame data/snapshot data.

Note

• Recording can be facilitated using the screen capture function of the PC.

—

Go to the next step.

VERIFY RELATED REPAIR INFORMATION OR SERVICE INFORMATION AVAILABILITY

• Verify related Service Bulletins, on-line repair information, or Service Information availability.

• Is any related Information available?

Yes

Perform repair or diagnosis according to the available information.

• If the vehicle is not repaired, go to the next step.

Go to the next step.

INSPECT FOR OTHER RELATED DTCs

• Perform the DTC inspection for the PCM.

(See DTC INSPECTION.)

• Are any other DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

(See DTC TABLE [PCM (SKYACTIV-X)].)

Go to the next step.

INSPECT PCM FOR MALFUNCTION DEPENDING ON REPEATABILITY

• Install/connect the part removed/disconnected during the troubleshooting procedure.

• Clear the DTC recorded in the memory.

(See CLEARING DTC.)

• Perform the DTC inspection for the PCM.

(See DTC INSPECTION.)

• Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

• If the malfunction recurs, replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)

Perform the repair completion verification 2.

Repair completion verification 1

VERIFY THAT VEHICLE IS REPAIRED

• Install/connect the part removed/disconnected during the troubleshooting procedure.

• Clear the DTC recorded in the memory.

(See CLEARING DTC.)

• Perform the DTC inspection for the PCM.

(See DTC INSPECTION.)

• Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(E)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

• If the malfunction recurs, replace the integrated starter generator (ISG), then go to the next step.

(See INTEGRATED STARTER GENERATOR (ISG) REMOVAL/INSTALLATION [SKYACTIV-X 2.0].)

Go to the next step.

Repair completion verification 2

VERIFY IF OTHER DTCs DISPLAYED

• Perform the DTC inspection.

(See DTC INSPECTION.)

• Are any other DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

DTC troubleshooting completed.

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