DTC P0AA0-00: Hybrid/EV Battery Positive Contactor Circuit Stuck Closed: Notes

1  . -

Outline of diagnosis: 

Even though the system main relay on the positive side of HV battery is tuned off, the voltage (VH)

in the inverter does not decrease

(1 trip detection logic)

Trouble symptom: 

Hybrid system stopped

Wiring diagram: 

Hybrid system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))> HYBRID ELECTRIC VEHICLE SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .

   Read the following DTCs using Subaru Select Monitor. Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to P-HEV DRIVE MOTOR (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   • P-HEV Hybrid Powertrain Control
   • P-HEV Drive Motor
   NOTE:

   Malfunction contents	System	Related DTC
   Microcomputer malfunction	P-HEV Hybrid Powertrain Control	P0606-47	HYBRID/EV POWERTRAIN CONTROL MODULE PROCESSOR WATCHDOG/SAFETY MCU FAILURE
   		P0606-87	HYBRID/EV POWERTRAIN CONTROL MODULE PROCESSOR TO MONITORING PROCESSOR MISSING MESSAGE
   		P060A-47	HYBRID/EV POWERTRAIN CONTROL MODULE MONITORING PROCESSOR WATCHDOG/SAFETY MCU FAILURE
   		P060A-87	HYBRID/EV POWERTRAIN CONTROL MODULE PROCESSOR FROM MONITORING PROCESSOR MISSING MESSAGE
   		P0A1B-49	DRIVE MOTOR "A" CONTROL MODULE INTERNAL ELECTRONIC FAILURE
   		P1C9E-9F	HYBRID/EV SYSTEM RESET STUCK OFF
   	P-HEV Drive Motor	P0A1B-1F	GENERATOR CONTROL MODULE CIRCUIT INTERMITTENT
   		P0A1A-47	GENERATOR CONTROL MODULE WATCHDOG/SAFETY MC FAILURE
   		P0A1A-49	GENERATOR CONTROL MODULE INTERNAL ELECTRONIC FAILURE
   		P1C2A-1C	GENERATOR A/D CONVERTER CIRCUIT CIRCUIT VOLTAGE OUT OF RANGE
   		P1C2A-49	GENERATOR A/D CONVERTER CIRCUIT INTERNAL ELECTRONIC FAILURE
   		P1C2B-1C	DRIVE MOTOR "A" CONTROL MODULE A/D CONVERTER CIRCUIT VOLTAGE OUT OF RANGE
   		P1C2B-49	DRIVE MOTOR "A" CONTROL MODULE A/D CONVERTER CIRCUIT INTERNAL ELECTRONIC FAILURE
   		P1CAC-49	GENERATOR POSITION SENSOR INTERNAL ELECTRONIC FAILURE
   		P1CAD-49	DRIVE MOTOR "A" POSITION SENSOR INTERNAL ELECTRONIC FAILURE
   		P1CAF-38	GENERATOR POSITION SENSOR REF SIGNAL CYCLE MALFUNCTION SIGNAL FREQUENCY INCORRECT
   		P1CB0-38	DRIVE MOTOR "A" POSITION SENSOR REF SIGNAL FREQUENCY INCORRECT
   		P3133-83	COMMUNICATION ERROR FROM GENERATOR TO DRIVE MOTOR "A" VALUE OF SIGNAL PROTECTION CALCULATION INCORRECT
   		P3133-86	COMMUNICATION ERROR FROM GENERATOR TO DRIVE MOTOR "A" SIGNAL INVALID
   		P3133-87	COMMUNICATION ERROR FROM GENERATOR TO DRIVE MOTOR "A" MISSING MESSAGE
   Power supply system malfunction	P-HEV Drive Motor	P06D6-1C	GENERATOR CONTROL MODULE OFFSET POWER CIRCUIT VOLTAGE OUT OF RANGE
   		P06B0-1C	GENERATOR CONTROL MODULE POSITION SENSOR REF POWER SOURCE CIRCUIT VOLTAGE OUT OF RANGE
   Communication system malfunction	P-HEV Hybrid Powertrain Control	P3123-87	LOST COMMUNICATION WITH DRIVE MOTOR CONTROL MODULE "A" FROM HYBRID/EV CONTROL MODULE MISSING MESSAGE
   Sensor and actuator circuit malfunction	P-HEV Hybrid Powertrain Control	P0AD9-11	HYBRID/EV BATTERY POSITIVE CONTACTOR CIRCUIT SHORT TO GROUND
   		P0AD9-15	HYBRID/EV BATTERY POSITIVE CONTACTOR CIRCUIT SHORT TO AUXILIARY BATTERY OR OPEN
   		P0ADD-11	HYBRID/EV BATTERY NEGATIVE CONTACTOR CIRCUIT SHORT TO GROUND
   		P0ADD-15	HYBRID/EV BATTERY NEGATIVE CONTACTOR CIRCUIT SHORT TO AUXILIARY BATTERY OR OPEN
   		P0AE4-11	HYBRID/EV BATTERY PRECHARGE CONTACTOR CIRCUIT SHORT TO GROUND
   		P0AE4-15	HYBRID/EV BATTERY PRECHARGE CONTACTOR CIRCUIT SHORT TO AUXILIARY BATTERY OR OPEN
   	P-HEV Drive Motor	P0A3F-16	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0A4B-16	GENERATOR POSITION SENSOR CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0A4B-21	GENERATOR POSITION SENSOR SIGNAL AMPLITUDE < MINIMUM
   		P0A4B-22	GENERATOR POSITION SENSOR SIGNAL AMPLITUDE>MAXIMUM
   		P0C50-13	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "A" CIRCUIT OPEN
   		P0C50-16	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "A" CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0C50-17	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "A" CIRCUIT VOLTAGE ABOVE THRESHOLD
   		P0C5A-13	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "B" CIRCUIT OPEN
   		P0C5A-16	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "B" CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0C5A-17	DRIVE MOTOR "A" POSITION SENSOR CIRCUIT "B" CIRCUIT VOLTAGE ABOVE THRESHOLD
   		P0C64-13	GENERATOR POSITION SENSOR CIRCUIT "A" CIRCUIT OPEN
   		P0C64-16	GENERATOR POSITION SENSOR CIRCUIT "A" CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0C64-17	GENERATOR POSITION SENSOR CIRCUIT "A" CIRCUIT VOLTAGE ABOVE THRESHOLD
   		P0C69-13	GENERATOR POSITION SENSOR CIRCUIT "B" CIRCUIT OPEN
   		P0C69-16	GENERATOR POSITION SENSOR CIRCUIT "B" CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0C69-17	GENERATOR POSITION SENSOR CIRCUIT "B" CIRCUIT VOLTAGE ABOVE THRESHOLD
   System malfunction	P-HEV Hybrid Powertrain Control	P0D2D-1C	DRIVE MOTOR "A" INVERTER VOLTAGE SENSOR VOLTAGE OUT OF RANGE
   		P1C83-49	HIGH VOLTAGE POWER RESOURCE CIRCUIT VOLTAGE SENSOR AFTER BOOSTING MALFUNCTION
   		P0C76-00	HYBRID/EV BATTERY SYSTEM DISCHARGE TIME TOO LONG
   	P-HEV Drive Motor	P0D2D-16	DRIVE MOTOR "A" INVERTER VOLTAGE SENSOR(VH) CIRCUIT VOLTAGE BELOW THRESHOLD
   		P0D2D-17	DRIVE MOTOR "A" INVERTER VOLTAGE SENSOR(VH) CIRCUIT VOLTAGE ABOVE THRESHOLD
   		P1CB6-9E	DRIVE MOTOR "A" INVERTER VOLTAGE SENSOR(VH) STUCK ON

   DTC P0AA0-00 may be output simultaneously due to the fault that DTC above describes.

   When "Only DTC P0AA0-00 is displayed" or "DTC other than above is displayed", go to  A.

   When DTCs related to [P-HEV Hybrid Powertrain Control] mentioned above are simultaneously displayed, go to  B.

   When DTCs related to [P-HEV Drive Motor] mentioned above are simultaneously displayed, go to  C.

   Yes: 

   1. Go to  2.
   2. Perform the diagnosis for the simultaneously displayed DTCs.
      NOTE:

      If more than one DTC is simultaneously displayed, perform the diagnosis in the order described in the above. 

   3. Perform the diagnosis for the simultaneously displayed DTCs.
      NOTE:

      If more than one DTC is simultaneously displayed, perform the diagnosis in the order described in the above. 

   No:  -

2. CHECK FREEZE FRAME DATA  .

   Read the freeze frame data value of [P-HEV Hybrid Powertrain Control] using the Subaru Select Monitor. Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>FREEZE FRAME DATA .

   Is the deviation between [VL-Voltage before Boosting] and [VH-Voltage after Boosting] at "0(s)" when DTC is confirmed less than 76 V?

   Yes:  Go to  3.

   No:  Replace Inverter with converter assembly. Ref. to HYBRID ELECTRIC VEHICLE>INVERTER AND CONVERTER ASSEMBLY .

   NOTE:

   When the voltage after boosting is occurring even though the system main relay (+ side) OFF command is issued, DTC P0AA0-00 is displayed. When the difference between the voltage before boosting and voltage after boosting is large, it is judged as a malfunction of the inverter (VH sensor). 

3. CHECK CONNECTION CONDITION OF CONNECTOR (Hybrid vehicle control ECU assembly CONNECTOR)  .

   Check the connecting condition of connector (i369) in Hybrid vehicle control ECU assembly and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matter Ref. to HYBRID ELECTRIC VEHICLE>INVERTER AND CONVERTER ASSEMBLY .

   Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

   Yes:  Connect the connector securely. And then Go to  4.

   No:  Go to  4.

4. CHECK CONNECTION CONDITION OF CONNECTOR (Rear harness LH CONNECTOR)  .

   Check the connecting condition of connector (R467) in Rear harness LH and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matters.

   Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

   Yes:  Connect the connector securely. Or, repair or replace the connector.

   And then Go to  5.

   No:  Go to  5.

5. CHECK CONNECTION CONDITION OF CONNECTOR (Rear harness LH CONNECTOR)  .

   Check the connecting condition of connector (R534) in Rear harness LH and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matters.

   Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

   Yes:  Connect the connector securely. Or, repair or replace the connector. And then Go to  6.

   No:  Go to  6.

6. CHECK CONNECTION CONDITION OF CONNECTOR (HV battery junction block CONNECTOR)  .
   CAUTION:

   Make sure to wear insulated gloves and protective goggles during the work. 

   1. Check that the Service plug is disconnected. Ref. to HYBRID ELECTRIC VEHICLE>SERVICE PLUG .
   2. Check the connecting condition of connector (HV49) in HV battery junction block and check the relevant terminals for contact pressure, deformation and intrusion of water or foreign matters.

      Is there looseness at the connector connection, or any poor contact, deformation or intrusion of water or foreign matters at the relevant terminals?

      Yes:  Connect the connector securely. And then Go to  7.

      No:  Go to  7.

7. CHECK GROUNDING POINT CONNECTION (LOW VOLTAGE CIRCUIT FOR SMR DRIVING)  .

   Check the connection of the grounding points (GB-9), (GB-10), (GB-14) and (GB-15) of the low voltage circuit for SMR driving.

   Is the grounding point connected securely?

   Yes:  Go to  8.

   No:  Connect the grounding point securely. And then Go to  9.

8. CHECK Wire harness AND CONNECTOR (Hybrid vehicle control ECU assembly - HV battery junction block) (OPEN CIRCUIT)  .
   CAUTION:

   Make sure to wear insulated gloves and protective goggles during the work. 

   1. Disconnect HV battery junction block connector (HV49).
   2. Disconnect Hybrid vehicle control ECU assembly connector (i369).
   3. Using a tester, measure the resistance between Hybrid vehicle control ECU assembly connector and HV battery junction block connector.

      Connector and terminal 

      (HV49) No. 1 - (i369) No. 5:

      Is the resistance less than 1 Ω?

      Yes:  Go to  9.

      No:  Repair or replace the Wire harness between Hybrid vehicle control ECU assembly connector and HV battery junction block connector.

      And then Go to  9.

9. CHECK Wire harness AND CONNECTOR (Hybrid vehicle control ECU assembly - HV battery junction block) (LINE-TO-LINE SHORT)  .
   CAUTION:

   Make sure to wear insulated gloves and protective goggles during the work. 

   Using a tester, measure the resistance between Hybrid vehicle control ECU assembly connector terminals.

   Connector and terminal 

   (i369) No. 5 - (i369) No. 1 - 35:

   Is the resistance 10 kΩ or more?

   Yes:  Go to  10.

   No:  Repair or replace the Wire harness between Hybrid vehicle control ECU assembly connector and HV battery junction block connector.

   And then Go to  10.

10. CHECK Wire harness AND CONNECTOR (HV battery junction block - CHASSIS GROUND) (OPEN CIRCUIT)  .
    CAUTION:

    Make sure to wear insulated gloves and protective goggles during the work. 

    1. Disconnect HV battery junction block connector (HV49).
    2. Using a tester, measure the resistance between HV battery junction block connector and chassis ground.

       Connector and terminal 

       (HV49) No. 2 - Chassis ground:

       Is the resistance less than 1 Ω?

       Yes:  Go to  11.

       No:  Repair or replace Wire harness between HV battery junction block connector and chassis ground.

       And then Go to  11.

11. CHECK HV battery junction block UNIT (SMRB)  .
    CAUTION:

    Make sure to wear insulated gloves and protective goggles during the work. 

    Using a tester, measure the resistance between HV battery junction block terminals.

    Connector and terminal 

    (HV49) No. 1 - (HV49) No. 2:

    Is the resistance 25.0 - 59.0 Ω? (When -40 - 80°C (-40 - 176°F))

    Yes:  Go to  12.

    No:  Go to  13.

12. CHECK HV battery junction block (SMRB)  .
    CAUTION:

    • Make sure to wear insulated gloves and protective goggles during the work. 
    • If SMR is welded, it may be removed from the welded position with a small vibration. Therefore, check while it is installed in the vehicle. 
    1. Disconnect connectors (HV43) and (HV44) from HV battery junction block.
       CAUTION:

       Be sure to insulate the disconnected high voltage connector by wrapping it with insulating tape. To do this, wrap the insulating tape from Wire harness along to the connector. 

    2. Using a tester, measure the resistance between HV battery junction block terminals.

       Connector and terminal 

       (HV44) No. 1 - (HV43) No. 1:

       Is the resistance 10 kΩ or more?

       NOTE:

       A resistance value of 10 kΩ or more indicates a past malfunction. A resistance value of less than 10 kΩ indicates a current malfunction. 

       Yes:  Go to  13.

       No:  Go to  13.

13. REPLACEMENT OF HV battery junction block  .
    CAUTION:

    Make sure to wear insulated gloves and protective goggles during the work. 

    1. Replace HV battery junction block. Ref. to HYBRID ELECTRIC VEHICLE>RELAY AND FUSE .
    2. Restore the vehicle to its original state.
    3. Attach the Service plug.
    4. Turn to IG ON.
    5. Using the Subaru Select Monitor, perform the clear memory of [P-HEV Hybrid Powertrain Control] Ref. to COMMON (DIAG)>CLEAR MEMORY .
    6. Turn to IG OFF, and wait for two minutes or more.
    7. Turn to READY ON.
    8. Using the Subaru Select Monitor, display the following items in the [Data Monitor] of [P-HEV Hybrid Powertrain Control], and record them. Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DATA MONITOR .
    • VL-Voltage before Boosting
    • Hybrid Battery Voltage

    Is the difference of the data between [Hybrid Battery Voltage] and [VL-Voltage before Boosting] less than 100 V constantly?

    Yes:  There was something wrong with HV battery junction block.

    Finish the diagnosis.

    No:  Replace Hybrid vehicle control ECU assembly and HV battery junction block. Ref. to HYBRID ELECTRIC VEHICLE>HYBRID POWERTRAIN CONTROL MODULE .