DTC P0AA0-00: Hybrid/EV Battery Positive Contactor Circuit Stuck Closed [12/2019 - 11/2023]: Procedure

1. Check for DTCs.

   Powertrain > Hybrid Control > Trouble Codes 

   Powertrain > Motor Generator > Trouble Codes 

   Result

   Result	Proceed to
   P0AA0-00 only is output, or DTCs except the ones in the table below are also output.	A
   DTCs of Hybrid Control System in the tables below are output.	B
   DTCs of Motor Generator Control System in the tables below are output.	C

   Malfunction Content	System	Relevant DTC
   Microcomputer malfunction	Hybrid Control System	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
   	Motor Generator Control System	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 source circuit malfunction	Motor Generator Control System	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	Hybrid Control System	P3123-87	Lost Communication with Drive Motor Control Module "A" from Hybrid/EV Control Module Missing Message
   Sensor and actuator circuit malfunction	Hybrid Control System	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
   	Motor Generator Control System	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	Hybrid Control System	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
   	Motor Generator Control System	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

   HINT: 

   • P0AA0-00 may be output as a result of the malfunction indicated by the DTCs above.
     1. The chart above is listed in inspection order of priority.
     2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)
2. Turn the ignition switch off.

Result: 

B 

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 

Refer to DIAGNOSTIC TROUBLE CODE CHART [12/2019 - 09/2020] , or refer to DIAGNOSTIC TROUBLE CODE CHART [09/2020 - 10/2021] , or refer to DIAGNOSTIC TROUBLE CODE CHART [10/2021 - 11/2023]

Result: 

C 

GO TO DTC CHART (MOTOR GENERATOR CONTROL SYSTEM)  . Refer to DIAGNOSTIC TROUBLE CODE CHART [12/2019 - 10/2021] , or refer to DIAGNOSTIC TROUBLE CODE CHART [10/2021 - 11/2023]

Result: 

A 

See step  2

1. Read the Freeze Frame Data of DTC P0AA0-00.

   Powertrain > Hybrid Control > Trouble Codes 

   NOTE:

   As freeze frame data is stored immediately before and after a DTC is stored, make sure to only read the values for the moment the DTC was stored ("0(s)").

   Result

   Result	Proceed to
   Difference between "VL-Voltage before Boosting" and "VH-Voltage after Boosting" is less than 76 V.	A
   Difference between "VL-Voltage before Boosting" and "VH-Voltage after Boosting" is 76 V or more.	B

   HINT: 

   If VH-Voltage after Boosting is output even when an off command is being sent to the system main relay (positive side), P0AA0-00 is output. If the difference between the "VL-Voltage before Boosting" and the "VH-Voltage after Boosting" is large, it is determined that there is an inverter (VH sensor) malfunction.

2. Turn the ignition switch off.

Result: 

B 

REPLACE INVERTER WITH CONVERTER ASSEMBLY 

Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

Result: 

A 

See step  3

Refer to PROCEDURE - Step 1

Result

Result: 

OK 

See step  5

Result: 

NG 

See step  4

Result

Result: 

NEXT 

See step  5

1. Check the connection condition of the AM8 floor wire connector and the contact pressure of each terminal. Check the terminals for deformation, and check the connector for water ingress and foreign matter.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [12/2019 - ]

   OK

   - The connector is connected securely.

   - The terminals are not deformed and are connected securely.

   - No water or foreign matter in the connector.

   Result

   Result	Proceed to
   OK	A
   NG (The connector is not connected securely.)	B
   NG (The terminals are not making secure contact or are deformed, or water or foreign matter exists in the connector.)	C

Result: 

A 

See step  8

Result: 

C 

See step  7

Result: 

B 

See step  6

Result

Result: 

NEXT 

See step  8

Result

Result: 

NEXT 

See step  8

1. Check that the service plug grip is not installed.
   NOTE:

   After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair information because this may cause a malfunction.

2. Remove the No. 10 HV battery shield panel.

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

3. Check the connector connections and contact pressure of the relevant terminals of the M56 HV battery junction block assembly connector.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [12/2019 - ]

   OK

   The connectors are connected securely and there are no contact pressure problems.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

4. Install the No. 10 HV battery shield panel.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  10

Result: 

NG 

See step  9

Result

Result: 

NEXT 

See step  10

1. Check the installation condition of the ground wire MF.

   OK

   The ground wire MF is securely installed.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  12

Result: 

NG 

See step  11

Result

Result: 

NEXT 

See step  12

1. Check that the service plug grip is not installed.
   NOTE:

   After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair information because this may cause a malfunction.

2. Remove the No. 10 HV battery shield panel.

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

3. Disconnect the M56 HV battery junction block assembly connector.
4. Disconnect the A32 hybrid vehicle control ECU connector.
5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A32-16 (SMRB) - M56-1 (SMRB)	Ignition switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A32-16 (SMRB) or M56-1 (SMRB) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Hybrid Vehicle Control ECU)
   *b	Front view of wire harness connector (to HV Battery Junction Block Assembly)

6. Reconnect the A32 hybrid vehicle control ECU connector.
7. Reconnect the M56 HV battery junction block assembly connector.
8. Install the No. 10 HV battery shield panel.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  14

Result: 

NG 

See step  13

Result

Result: 

NEXT 

See step  14

1. Check that the service plug grip is not installed.
   NOTE:

   After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair information because this may cause a malfunction.

2. Remove the No. 10 HV battery shield panel.

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

3. Disconnect the M56 HV battery junction block assembly connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M56-3 (GND) - Body ground	Ignition switch off	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to HV Battery Junction Block Assembly)

5. Reconnect the M56 HV battery junction block assembly connector.
6. Install the No. 10 HV battery shield panel.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  16

Result: 

NG 

See step  15

Result

Result: 

NEXT 

See step  16

1. Check that the service plug grip is not installed.
   NOTE:

   After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair information because this may cause a malfunction.

2. Remove the No. 10 HV battery shield panel.

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

3. Disconnect the M56 HV battery junction block assembly connector.
4. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component without harness connected (HV Battery Junction Block Assembly)

   -

   -

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M56-1 (SMRB) - M56-3 (GND)	-40 to 80°C (-40 to 176°F)	25.0 to 59.0 Ω

5. Reconnect the M56 HV battery junction block assembly connector.
6. Install the No. 10 HV battery shield panel.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  19

Result: 

OK 

See step  17

1. Check that the service plug grip is not installed.
   NOTE:

   After removing the service plug grip, do not turn the ignition switch to ON (READY), unless instructed by the repair information because this may cause a malfunction.

2. Remove the No. 10 HV battery shield panel.

   Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

3. Disconnect the 2 HV floor under wire connectors from the HV battery junction block assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

4. Disconnect the 2 HV battery high voltage connectors from the HV battery junction block assembly.
   NOTE:

   Insulate each disconnected high-voltage connector with insulating tape. Wrap the connector from the wire harness side to the end of the connector.

5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   k2-1 (CBI) - z11-1 (+)	Ignition switch off	10 kΩ or higher

   HINT: 

   • If a system main relay is stuck closed, inspect the HV battery junction block assembly without removing it from the vehicle, in order to keep the relay closed.
   • If the result of reading the freeze frame data is A, the HV battery junction block assembly must be replaced. Measuring resistance can determine that this is either a present or past malfunction.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (HV Battery Junction Block Assembly)

6. Reconnect the 2 HV battery high voltage connectors.
7. Reconnect the 2 HV floor under wire connectors.
8. Install the No. 10 HV battery shield panel.

   Result

   Result	Judgment	Proceed to
   OK	Past malfunction	A
   NG	Present malfunction	B

Result: 

B 

See step  20

Result: 

A 

See step  18

Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

Result

Result: 

NEXT 

See step  21

Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

Result

Result: 

NEXT 

See step  21

Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

Result

Result: 

NEXT 

See step  21

1. Install the service plug grip.
2. Clear the DTCs.

   Powertrain > Hybrid Control > Clear DTCs 

3. Turn the ignition switch off and wait for 2 minutes or more.
4. Turn the ignition switch to ON (READY).
5. According to the display on the GTS, read the Data List and monitor the values of "Hybrid Battery Voltage" and "VL-Voltage before Boosting" for 3 minutes.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   VL-Voltage before Boosting
   Hybrid Battery Voltage

   Result

   Result	Proceed to
   Difference between "Hybrid Battery Voltage" and "VL-Voltage before Boosting" is always less than 100 V.	A
   Difference between "Hybrid Battery Voltage" and "VL-Voltage before Boosting" is 100 V or more.	B

6. Turn the ignition switch off.

Result: 

A 

END 

Result: 

B 

REPLACE HYBRID VEHICLE CONTROL ECU AND HV BATTERY JUNCTION BLOCK ASSEMBLY 

HYBRID VEHICLE CONTROL ECU: Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

HV BATTERY JUNCTION BLOCK ASSEMBLY: Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]