Home

Mazdamanuals.com

DTC U0401:00 [INTEGRATED STARTER GENERATOR (ISG)]

DTC U0401:00 [INTEGRATED STARTER GENERATOR (ISG)]


id140202302000


Outline

System malfunction location

Error signal received from PCM

Detection condition
Determination conditions
•  The integrated starter generator (ISG) receives an error signal from the PCM for 1 s.
Precondition
•  1.5 s have elapsed after the ignition was switched ON (engine off or on)
•  The initialization for the stator coil drive circuit in the integrated starter generator (ISG) is completed.
•  The voltage at terminal 1A is 10 V or more for a continuous 1.5 s.
Fail-safe
•  Stops power supply from the Mazda M Hybrid battery and supplies power to the vehicle’s electrical devices (12 V power supply) from the 12 V battery.(If the vehicle continues to be driven while the DTC is detected, the 12 V battery will be depleted and the vehicle can no longer be driven.)
•  Inhibits the i-stop control.
•  Inhibits the non-power generation control.
•  Inhibits regenerative braking by the integrated starter generator (ISG).
•  Inhibits motor assist control by the integrated starter generator (ISG).
Possible cause
•  PCM malfunction
•  Integrated starter generator (ISG) malfunction
System wiring diagram
•  Not applicable
Connector diagram
•  Not applicable


Diagnostic Procedure

Step

Inspection

Results

Action

1
RECORD VEHICLE STATUS WHEN DTC WAS DETECTED TO UTILIZE WITH REPEATABILITY VERIFICATION
•  Record the snapshot data.
Note
•  Recording can be facilitated using the screen capture function of the PC.
Go to the next step.
2
VERIFY PCM DTC
•  Perform the DTC inspection for the PCM.
•  Are any DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
No
Go to the next step.
3
INSPECT PCM FOR MALFUNCTION DEPENDING ON REPEATABILITY
•  Install/connect the part removed/disconnected during the troubleshooting procedure.
•  Clear the DTC recorded in the memory.
•  Switch the ignition off, then ON (engine off).
•  Perform the DTC inspection for the integrated starter generator (ISG).
•  Is the same Pending DTC present?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
If the CAN communication is normal, perform the diagnosis from Step 1.
Go to repair completion verification 1.
No
Go to the next step.
4
INSPECT PCM FOR MALFUNCTION DEPENDING ON REPEATABILITY AGAIN
•  Perform the "Action for Non-repeatable Malfunction" procedure.
•  Perform the DTC inspection for the integrated starter generator (ISG).
•  Is the same Pending DTC present?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
If the CAN communication is normal, perform the diagnosis from Step 1.
Go to repair completion verification 1.
No
The system is normal. (Explain to the customer that a malfunction was detected temporarily, but the vehicle is currently normal.)
Go to 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.
•  Replicate the vehicle conditions at the time the DTC was detected using the following procedure.
―  Switch the ignition off, then ON (engine off).
•  Perform the DTC inspection for the integrated starter generator (ISG).
•  Is the same Pending DTC present?
Yes
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
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.
No
Go to the next step.
Repair completion verification 2
VERIFY IF OTHER DTCs DISPLAYED
•  Perform the DTC inspection.
•  Are any other DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.