Inspection Procedure

CAUTION:

Turn the ignition switch off before inspecting the high-voltage system. Take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are working on the high-voltage system.
After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.

HINT:

At least 5 minutes is required to discharge the high-voltage capacitor inside the w/ converter inverter assembly.
If DTC P0A78-305, P0A7A-343, or P0A79-697 is output together with P3233-750, the HSDN circuit may be shorted to +B.

CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - MG ECU)

CAUTION: Be sure to wear insulated gloves.

Turn the ignition switch off and remove the service plug grip. (See HYBRID CONTROL SYSTEM )
Disconnect the H34 connector from the HV control ECU.
NOTE: Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.
Remove the inverter cover. (See INVERTER WITH CONVERTER )
NOTE:
- Wrap the interlock round terminal for the inverter cover with vinyl tape to prevent it from shorting to ground.
- Be sure to prevent water in the reservoir tank from entering the inverter.
- Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.
Disconnect the I21 connector from the w/ converter inverter assembly (MG ECU).

Measure the voltage according to the value(s) in the table below when the ignition switch is in the ON position.

Fig 1: Disconnecting H34 Connector From HV Control ECU

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard Resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
HSDN (H34-21) - Body ground	Below 1 V

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

Standard Resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection HV ECU - MG ECU	Specified Condition
HSDN (H34-21) - HSDN (I21-26)	Below 1 Ω

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK W/ CONVERTER INVERTER ASSEMBLY

CAUTION: Be sure to wear insulated gloves.

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

Standard Resistance

TESTER CONNECTION AND SPECIFIED CONDITION

Tester Connection	Specified Condition
HSDN (I21-26) - +B (I21-7)	10 kΩ or higher
HSDN (I21 -26) - +B2 (I21-4)	10 kΩ or higher

NG: REPLACE W/ CONVERTER INVERTER ASSEMBLY

Fig 2: Disconnecting I21 Connector From W/ Converter Inverter Assembly

OK: REPLACE HYBRID VEHICLE CONTROL ECU