Inspection Procedure

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

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.

CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)
CAUTION:
Be sure to wear insulated gloves.
1. Turn the ignition switch off and remove the service plug grip. (See PRECAUTION )
  NOTE: Do not put the vehicle into the READY-on state with the service plug grip removed as this may cause a malfunction.
2. 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.
  - 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.
3. Check the connections of the MG ECU connectors.
  OK:
  
  Connectors are connected securely and there is no poor connection.
Fig 1: Checking Connection Condition Of MG ECU Connector (Looseness And Poor Contact)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONNECT SECURELY

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (IGCT RELAY - MG ECU)

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Remove the IGCT relay from the engine room R/B No. 2.
Disconnect the I21 connector from the MG ECU.

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

Standard Resistance (Check for open)

IGCT RELAY - MG ECU (CHECK FOR OPEN)

Tester Connection	Specified Condition
+B (I21-7) - Engine room R/B No. 2 IGCT relay terminal 5	Below 1 Ω
+B2 (I21-4) - Engine room R/B No. 2 IGCT relay terminal 5	Below 1 Ω

Standard Resistance (Check for short)

IGCT RELAY - MG ECU (CHECK FOR SHORT)

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

Fig 2: Checking Harness And Connector (IGCT Relay - MG ECU)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: GO TO NEXT STEP

INSPECT MG ECU (+B VOLTAGE)

CAUTION:

Be sure to wear insulated gloves.

Check that the service plug grip is removed.

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

Standard Voltage

MG ECU (+B VOLTAGE)

Tester Connection	Specified Condition
+B (I21-7) - Body ground	10 V or more
+B2 (I21-4) - Body ground	10 V or more

Fig 3: Inspecting MG ECU (+B Voltage)

NOTE: Turning the ignition switch to the ON position with the service plug and inverter cover removed causes interlock switch system DTCs to be stored. Clear the DTCs after performing the inspection.

NG: CHECK AND REPLACE BATTERY

OK: REPLACE W/ CONVERTER INVERTER ASSEMBLY