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

NG → CONNECT SECURELY 

OK: Go to next step 

NG → CONNECT SECURELY 

OK: Go to next step 

1. Turn the ignition switch to ON.
2. Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below, and measure the waveform.
   Fig 1: Checking Hybrid Vehicle Control ECU With Waveform Reference

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Item	Content
   Terminal	A65-11 (VLO) - D72-6 (E1)
   Equipment Setting	5 V/DIV., 50 ms/DIV.
   Condition	Ignition switch ON

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Hybrid Vehicle Control ECU)

   OK

   The waveform appears as shown in the illustration.

   HINT: 

   • Perform this inspection with the hybrid vehicle control ECU connector connected.
3. Turn the ignition switch off.

NG → See step   7 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
4. Read and record the DTCs and freeze frame data.
5. Clear DTCs and freeze frame data.

NEXT: Go to next step 

1. Turn the ignition switch to ON (READY).
2. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
3. Check if DTCs are output.

   Result

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

4. Turn the ignition switch off.

B → See step   9 

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   9 

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. Disconnect the A64 connector from the inverter with converter assembly.
3. Measure the resistance according to the value(s) in the table below.
   Fig 2: Measuring Resistance Of Inverter With Converter Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   A64-4 (VLO) - Body ground	Ignition switch off	370 to 430 kΩ

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Inverter with Converter Assembly)

4. Connect the inverter with converter assembly connector.

NG → See step   8 

OK → See step   10 

1. Disconnect the A64 connector from the inverter with converter assembly.
2. Disconnect the A65 connector from the hybrid vehicle control ECU.
3. Measure the resistance according to the value(s) in the table below.
   Fig 3: Checking Harness And Connector (Inverter With Converter - Hybrid Vehicle Control ECU)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   A64-4 (VLO) - A65-11 (VLO)	Ignition switch off	Below 1 Ω
   A64-4 (VLO) or A65-11 (VLO) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Inverter with Converter Assembly)
   *b	Rear view of wire harness connector (to Hybrid Vehicle Control ECU)

4. Connect the inverter with converter assembly connector.
5. Connect the hybrid vehicle control ECU connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   9