DTC P0A1F-94: Hybrid/EV Battery Energy Control Module Unexpected Operation [11/2021 - ]: Procedure

Pre-procedure1

1. None.

   Procedure1

2. Read and record the DTCs and freeze frame data.

   Powertrain > Hybrid Control > Trouble Codes 

   Powertrain > HV Battery > Trouble Codes 

   Result

   Result	Proceed to
   P0A1F-94 only is output, or DTCs except the ones in the table below are also output.	A
   DTCs of hybrid control system except P0A1F-94 are output.	B
   Any of the following DTCs including pending DTCs are also output.	C

   System	Relevant DTC
   Hybrid battery system	P1A00-1C	Hybrid Battery Stack 2 Cell Voltage Detection Voltage Out of Range
   	P301A-1C	Hybrid Battery Stack 1 Cell Voltage Detection Voltage Out of Range

   Post-procedure1

3. Turn the ignition switch off.

Result: 

A 

REPLACE BATTERY ECU ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

Result: 

B 

GO TO DTC CHART (HYBRID CONTROL SYSTEM) 

Result: 

C 

See step  2

1. Check the DTCs that were output when the vehicle was brought to the workshop.

   Result

   Result	Proceed to
   "P1A00-1C" is also output.	A
   "P301A-1C" is also output.	B

Result: 

B 

See step  6

Result: 

A 

See step  3

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. Check the connector connections and contact pressure of the relevant terminals for the battery ECU assembly.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [11/2021 - ]

   OK

   The connector is connected securely and there are no contact problems.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Result

   Result		Proceed to
   OK		A
   Not connected securely	The terminals are not damaged or corroded	B
   Not connected securely	The terminals are damaged or corroded	C

Result: 

B 

CONNECT SECURELY 

Result: 

C 

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

Result: 

A 

See step  4

1. Read the value of freeze frame data items "Hybrid/EV Battery Cell 36 Voltage" through "Hybrid/EV Battery Cell 70 Voltage" for DTC P1A00-1C and make a note if the value of any is 1.6 V or less.

   Powertrain > HV Battery > Trouble Codes 

2. Turn the ignition switch off.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

Refer to PROCEDURE - Step 7

Result

Result: 

A 

REPLACE NO. 2 HV SUPPLY STACK SUB-ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

Result: 

B 

REPLACE BATTERY ECU ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

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. Check the connector connections and contact pressure of the relevant terminals for the battery ECU assembly.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [11/2021 - ]

   OK

   The connector is connected securely and there are no contact problems.

   Result

   Result		Proceed to
   OK		A
   Not connected securely	The terminals are not damaged or corroded	B
   Not connected securely	The terminals are damaged or corroded	C

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Result: 

B 

CONNECT SECURELY 

Result: 

C 

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

Result: 

A 

See step  7

1. Read the value of freeze frame data items "Hybrid/EV Battery Cell 1 Voltage" through "Hybrid/EV Battery Cell 35 Voltage" for DTC P301A-1C and make a note if the value of any is 1.6 V or less.

   Powertrain > HV Battery > Trouble Codes 

2. Turn the ignition switch off.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  8

Refer to PROCEDURE - Step 4

Result

Result: 

A 

REPLACE NO. 1 HV SUPPLY STACK SUB-ASSEMBLY 

Refer to REMOVAL [11/2021 - ]

Result: 

B 

REPLACE BATTERY ECU ASSEMBLY 

Refer to REMOVAL [11/2021 - ]