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 QUANTITY OF HV COOLANT
1. Check the inverter coolant level.
  OK:
  
  There is sufficient amount of coolant for the inverter.
NG: CHECK FOR COOLANT LEAKS AND ADD COOLANT

OK: GO TO NEXT STEP
CHECK COOLANT HOSE
1. Check that the hoses of the cooling system are not bent or clogged.
  OK:
  
  The hoses of the cooling system are not bent or clogged.
Fig 1: Checking Coolant Hose
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CORRECT TO NORMAL CONDITION

OK: GO TO NEXT STEP
CHECK CONNECTION CONDITION OF WATER PUMP CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connection of the water pump w/ motor & bracket assembly connector.
  OK:
  
  Connector is connected securely and there is no poor connection.
Fig 2: Checking Connection Of Water Pump W/ Motor & Bracket Assembly Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONNECT SECURELY

OK: GO TO NEXT STEP
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (WATER PUMP)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Select the following menu items: DIAGNOSIS / OBD/ MOBD / HV ECU / DATA LIST / WATER PUMP.
4. During the WATER PUMP active test, check operation of the water pump.
  OK:
  
  There are ripples in the reservoir tank coolant.
  
  HINT:
  
  The water pump is also activated in the READY-on state.
NG: CHECK WATER PUMP W/ MOTOR & BRACKET ASSEMBLY CIRCUIT

OK: GO TO NEXT STEP
CHECK CONNECTION CONDITION OF COOLING FAN CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connection of the electric cooling fan connector.
  OK:
  
  Connector is connected securely and there is no poor connection.
NG: CONNECT SECURELY

OK: GO TO NEXT STEP
PERFORM ACTIVE TEST BY INTELLIGENT TESTER (COOLING FAN)
1. Connect the intelligent tester to the DLC3.
2. Turn the ignition switch to the ON position.
3. Select the following menu items: DIAGNOSIS / ENHANCED OBDII / ENGINE / DATA LIST / COOLING FAN.
4. Perform the COOLING FAN active test.
  OK:
  
  The electric cooling fan rotates.
NG: CHECK COOLING FAN CIRCUIT

OK: GO TO NEXT STEP
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.
  - 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.
3. Check the connections of the MG ECU connectors.
  OK:
  
  Connectors are connected securely and there is no poor connection.
Fig 3: Checking Connection Condition Of MG ECU Connector (Looseness And Poor Contact)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONNECT SECURELY

OK: REPLACE W/ CONVERTER INVERTER ASSEMBLY