DTC P0AA0-00: Hybrid/EV Battery Positive Contactor Circuit Stuck Closed [11/2022 - ]: Procedure

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 [11/2022 - 12/2024] , or refer to REMOVAL [12/2024 - ]

Result: 

A 

See step  2

See step  1

Result

Result: 

OK 

See step  4

Result: 

NG 

See step  3

Result

Result: 

NEXT 

See step  4

1. Check the connection condition of the 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 [09/2021 - ]

   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  7

Result: 

C 

See step  6

Result: 

B 

See step  5

Result

Result: 

NEXT 

See step  7

Result

Result: 

NEXT 

See step  7

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 appropriate service information because this may cause a malfunction.

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

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2021 - ]

   OK

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  9

Result: 

NG 

See step  8

Result

Result: 

NEXT 

See step  9

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

   OK

   The ground wire OF is securely installed.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  11

Result: 

NG 

See step  10

Result

Result: 

NEXT 

See step  11

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 appropriate service information because this may cause a malfunction.

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

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   I249-3 (SMRB) - O212-4 (SMRB)	Ignition switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   I249-3 (SMRB) or O212-4 (SMRB) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

5. Reconnect the hybrid vehicle control ECU connector.
6. Reconnect the HV battery junction block assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  13

Result: 

NG 

See step  12

Result

Result: 

NEXT 

See step  13

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 appropriate service information because this may cause a malfunction.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O212-2 (GND) - Body ground	Ignition switch off	Below 1 Ω

4. Reconnect the HV battery junction block assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  15

Result: 

NG 

See step  14

Result

Result: 

NEXT 

See step  15

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 appropriate service information because this may cause a malfunction.

2. Disconnect the HV battery junction block assembly connector.
3. 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
   O212-4 (SMRB) - O212-2 (GND)	-40 to 80°C (-40 to 176°F)	20.6 to 40.8 Ω

4. Reconnect the HV battery junction block assembly connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  18

Result: 

OK 

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 appropriate service information because this may cause a malfunction.

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NOTE:

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

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   W7-1 (CBI) - z26-1 (+)	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)

4. Reconnect the HV battery high voltage connectors.

   Result

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

Result: 

B 

See step  19

Result: 

A 

See step  17

Refer to REMOVAL [11/2022 - ]

Result

Result: 

NEXT 

See step  20

Refer to REMOVAL [11/2022 - ]

Result

Result: 

NEXT 

See step  20

Refer to REMOVAL [11/2022 - ]

Result

Result: 

NEXT 

See step  20

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

   Powertrain > Hybrid Control > Clear DTCs 

3. Turn the ignition switch off and wait for 30 seconds or more.
4. Turn the ignition switch to ON (READY).
5. Turn the ignition switch off and wait for 30 seconds or more.
6. Turn the ignition switch to ON (READY).
7. Check for DTCs.

   Powertrain > Hybrid Control > Trouble Codes 

   Powertrain > Motor Generator > Trouble Codes 

   Powertrain > HV Battery > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTCs of Hybrid Control System are output.	B
   DTCs of Motor Generator Control System are output.	C
   DTCs of Hybrid Battery System are output.	D

8. Turn the ignition switch off.

Result: 

B 

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 

Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2022 - 12/2024] , or refer to DIAGNOSTIC TROUBLE CODE CHART [12/2024 - ]

Result: 

C 

GO TO DTC CHART (MOTOR GENERATOR CONTROL SYSTEM) 

Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2022 - ]

Result: 

D 

GO TO DTC CHART (HYBRID BATTERY SYSTEM) 

Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2022 - ]

Result: 

A 

See step  21

1. According to the display on the GTS, read the Data List and monitor the values of "Hybrid/EV Battery Voltage" and "VL-Voltage before Boosting" for 3 minutes.

   Powertrain > Hybrid Control > Data List 

   Tester Display
   VL-Voltage before Boosting
   Hybrid/EV Battery Voltage

   Result

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

2. 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 [11/2022 - 12/2024] , or refer to REMOVAL [12/2024 - ]

HV BATTERY JUNCTION BLOCK ASSEMBLY: Refer to REMOVAL [11/2022 - ]