DTC P0A11-12: DC/DC Converter Enable Circuit Short to Battery [12/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU ASSEMBLY CONNECTOR)

See step 1

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:

CONNECT SECURELY

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 2

CHECK CONNECTOR CONNECTION CONDITION (DC/DC CONVERTER ASSEMBLY CONNECTOR)
See step 2

Result

Proceed to

OK

NG

Result:

NG

CONNECT SECURELY

Result:

OK

See step 3
CLEAR DTC
See step 3

Result

Proceed to

NEXT

Result:

NEXT

See step 4

Proceed to
NEXT

CHECK DTC OUTPUT (HYBRID CONTROL)

Pre-procedure1

Depress the brake pedal and turn the ignition switch to ON (READY).
HINT:

Perform this step to check if the ignition switch can be turned to ON (READY).

Check for DTCs.

Powertrain > Hybrid Control > Trouble Codes

Result

Result	Proceed to
Ignition switch can be turned to ON (READY) and P0A11-12 is not output.	A
Ignition switch cannot be turned to ON (READY) and P0A11-12 is output.	B

Post-procedure1

Turn the ignition switch off.

Result:

USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2023 - ]

Result:

See step 5

CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (NODD)

WARNING:

Be sure to wear insulated gloves.

Pre-procedure1

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 service information because this may cause a malfunction.

Disconnect the DC/DC converter assembly connector.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Voltage

Tester Connection	Condition	Specified Condition	Result
I49-5 (NODD) - Body ground	Ignition switch ON	Below 1 V	V

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to DC/DC Converter Assembly)

NOTE:

Turning the ignition switch to ON with the DC/DC converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Result

Proceed to
OK
NG

Post-procedure1

Turn the ignition switch off.
Reconnect the DC/DC converter assembly connector.

Result:

REPLACE DC/DC CONVERTER ASSEMBLY. Refer to REMOVAL [12/2023 - ]

Result:

See step 6

CHECK HARNESS AND CONNECTOR (DC/DC CONVERTER ASSEMBLY - HYBRID VEHICLE CONTROL ECU ASSEMBLY)

WARNING:

Be sure to wear insulated gloves.

Pre-procedure1

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 service information because this may cause a malfunction.

Disconnect the DC/DC converter assembly connector.

Disconnect the hybrid vehicle control ECU assembly connector.
Turn the ignition switch to ON.

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

Front view of wire harness connector
(to DC/DC Converter Assembly)

Front view of wire harness connector
(to Hybrid Vehicle Control ECU Assembly)

Standard Voltage

Tester Connection	Condition	Specified Condition	Result
I49-5 (NODD) or B88-47 (NODD) - Body ground and other terminals	Ignition switch ON	Below 1 V	V

Result

Proceed to
OK
NG

Post-procedure1

Reconnect the hybrid vehicle control ECU assembly connector.
Reconnect the DC/DC converter assembly connector.

Result:

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to REMOVAL [12/2023 - ]

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR