DTC P3087-183: Open Circuit in DC / DC Converter EMPS: Procedure

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 low voltage connector of the power steering converter.
   Fig 1: Locating Power Steering Converter Low Voltage Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

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

NG → CONNECT SECURELY 

OK: Go to next step 

1. Turn the power switch off.
   Fig 2: Locating Power Steering Converter N1 Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the service plug grip. Refer to PRECAUTION .
3. Disconnect low voltage connector n1 from the power steering converter.

   HINT: 

   For the removal and installation procedures related to the low voltage connector of the power steering converter. Refer to REMOVAL .

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

   Standard resistance (Check for open)

   Tester Connection	Condition	Specified Condition
   n1-6 (DDOK) - Body ground	Power switch off	370 to 430 kΩ

NG → See step   4 

OK → See step   5 

1. Disconnect connector A75 from the hybrid vehicle control ECU.
2. Measure the resistance according to the value(s) in the table below.
   Fig 3: Identifying A75 And N1 Terminal Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance (Check for open)

   Tester Connection	Switch Condition	Specified Condition
   A75-21 (PSOK) - n1-6 (DDOK)	Power switch off	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Switch Condition	Specified Condition
   A75-21 (PSOK) or n1-6 (DDOK) - Body ground and other terminals	Power switch off	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6