DTC P0A09-591: DC / DC Converter Status Circuit Low Input: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Check if DTCs are output.

   Result

   Result	Proceed to
   P0A09-591 only is output.	A
   P0AE6-225 is also output.	B

B → See step   12 

A: Go to next step 

1. Check the connections of the hybrid vehicle control ECU connectors.

   OK

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

NG → CONNECT SECURELY 

OK: Go to next step 

1. Check the connection of the No. 2 battery pack wire connector.
   Fig 1: Locating No. 2 Battery Pack Wire Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

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

   HINT: 

   For the removal and installation procedures related to inspection of the connection of the No. 2 battery pack wire connector. Refer to REMOVAL .

NG → CONNECT SECURELY 

OK: Go to next step 

1. Connect an oscilloscope to the No. 2 battery pack wire connector terminals specified in the table below, and measure the waveform.
   Fig 2: Identifying NS1 No. 2 Battery Pack Wire Connector And Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Item	Contents
   Terminal	nS1-12 (VLO) - nS1-9 (GND)
   Equipment Setting	5 V/DIV., 50 ms./DIV.
   Condition	Power switch on (IG)

   OK

   The waveform appears as shown in the illustration.

   HINT: 

   • Perform this inspection with the No. 2 battery pack wire connected.
   • The waveform (duty) will vary depending on inspection conditions.

NG → See step   8 

OK: Go to next step 

1. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
2. Read and record the DTCs and freeze frame data.
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Clear DTCs and freeze frame data.

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
4. Check if DTCs are output.

   Result

   Result	Proceed to
   DTC P0A09-591 is not output.	A
   DTC P0A09-591 is output again.	B

B → See step   14 

A: Go to next step 

1. Check for intermittent problems. Refer to CHECK FOR INTERMITTENT PROBLEMS .

NG → REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA 

OK → See step   14 

1. Turn the power switch off.
2. Disconnect the No. 2 battery pack wire connector.
   Fig 3: Locating No. 2 Battery Pack Wire Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the resistance according to the value(s) in the table below.
   Fig 4: Identifying NS1 No. 2 Battery Pack Wire Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Switch Condition	Specified Condition
   nS1-12 (VLO) - Body ground	Power switch off	370 to 430 kΩ

NG → See step   11 

OK: Go to next step 

1. Turn the power switch off.
2. Remove the service plug grip. Refer to PRECAUTION .
   Fig 5: Locating Service Plug Grip

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Fig 6: Locating Service Plug Grip

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

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

3. Check the connection of the low voltage connector of the hybrid vehicle converter.

   OK

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

NG → CONNECT SECURELY 

OK: Go to next step 

1. Check that the service plug grip is not installed.
   Fig 7: Identifying NS1 No. 2 Battery Pack Wire Connector And Z92 Hybrid Vehicle Converter Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the low voltage connector from the hybrid vehicle converter.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Switch Condition	Specified Condition
   nS1-12 (VLO) - z82-11 (VLO)	Power switch off	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Switch Condition	Specified Condition
   nS1-12 (VLO) or z82-11 (VLO) - Body ground and other terminals	Power switch off	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   13 

1. Disconnect connector A74 from the hybrid vehicle control ECU.
   Fig 8: Identifying NS1 No. 2 Battery Pack Wire Connector And A74 Hybrid Vehicle Converter Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Switch Condition	Specified Condition
   A74-27 (VLO) - nS1-12 (VLO)	Power switch off	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Switch Condition	Specified Condition
   A74-27 (VLO) or nS1-12 (VLO) - Body ground and other terminals	Power switch off	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   14