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.

READ OUTPUT DTC (HV)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
Select the following menu items: DIAGNOSIS / OBD/ MOBD / HV ECU / DTC INFO / CURRENT CODES.

Read output DTCs. (See DTC CHECK / CLEAR )

Result:

The DTCs shown in the table below are output

OUTPUT DTC (HV)

DTC No.	Relevant Diagnosis
P0A1D	HV ECU circuit malfunction
P0A2B, P0A2C, P0A2D	Motor temperature sensor circuit
P0A37, P0A38, P0A39	Generator temperature sensor circuit
P0A3F, P0A40, P0A41	Motor resolver circuit
P0A4B, P0A4C, P0A4D	Generator resolver circuit
P0A60, P0A63	Motor current sensor circuit
P0A72, P0A75	Generator current sensor circuit
P0A78	Motor inverter function malfunction
P0A7A	Generator inverter function malfunction
P0A90	Motor function malfunction
P0A92	Generator function malfunction
P0A93	Inverter cooling system
P0A94	Boost converter circuit
P0AA1, P0AA2, P0AA4, P0AA5	System main relay circuit
P3000, P3003, P0AA6, P3110	High-voltage system
P0AEE, P0AEF, P0AF0	Motor inverter temperature sensor circuit
P3221	Generator inverter temperature sensor circuit
P3226	Boost converter temperature sensor circuit
P0A05	Water pump w/ Motor malfunction
P0A79	(Except for 692, 812, 813, and 814) Rear motor inverter function malfunction
P0AF3, P0AF4, P0AF5	Rear motor temperature sensor malfunction
P0A45, P0A46, P0A47	Rear motor resolver malfunction
P0A69, P0A6C, P0A55	Rear motor current sensor circuit
P0A1A, P0A1B, P0A1C	MG ECU malfunction

NOTE: If P0A79-692 is output, repair the malfunctioning area indicated by the DTC, or replace the w/converter inverter assembly after repairing the malfunctioning area.

HINT:

Turning the ignition switch to the ON position with the service plug grip and inverter cover removed causes interlock switch system DTC P0A0D-350 to be output.
P0A79-692 may be output due to a malfunction which causes the DTCs in the table above to be output. In this case, first troubleshoot the output DTCs in the table above. Then, perform a reproduction test to check that no DTCs are output.

YES: GO TO DIAGNOSTIC TROUBLE CODE CHART

NO: GO TO NEXT STEP

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 if 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 Condition Of Water Pump Connector (Looseness And Poor Contact)
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 / ACTIVE TEST / WATER PUMP.
4. During the WATER PUMP active test, check operation of the water pump w/ motor & bracket assembly.
  Result:
  
  There are ripples in the reservoir tank coolant.
NG: CHECK WATER PUMP W/ MOTOR & BRACKET ASSEMBLY CIRCUIT

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 / OBD/ MOBD / HV ECU / ACTIVE TEST / WATER PUMP.
4. Perform the electric cooling fan active test.
  OK:
  
  The electric cooling fan rotates.
NG: CHECK COOLING FAN CIRCUIT

OK: GO TO NEXT STEP
CHECK CONNECTION CONDITION OF HYBRID VEHICLE CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connections of all HV control ECU connectors.
  OK:
  
  Connectors are connected securely and there is no poor connection.
Fig 3: Checking Connection Condition Of Hybrid Vehicle Control ECU Connector (Looseness And Poor Contact)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONNECT SECURELY

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.
  - 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 4: 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

INSPECT REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Disconnect the three-phase AC cable of the Rear Motor from the inverter.

Fig 5: Identifying Rear Traction Motor W/Transaxle Assembly
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

Fig 6: Measuring Resistance Of Three-Phase AC Cable Of Rear Motor

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard Resistance

REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY (USING MILLIOHMMETER)

Tester Connection	Specified Condition
U - V	146 to 163 mΩ (20°C)
V - W	146 to 163 mΩ (20°C)
W - U	146 to 163 mΩ (20°C)

NOTE: If the Rear Motor temperature is too high, the resistance changes greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

To correct the resistance varying depending on the temperature, use the following formula to calculate the resistance at 20°C.
HINT:
- R20 = Rt / {1 + 0.00393 X (T - 20)}
- R20: Resistance at 20 °C (mΩ)
- Rt: Measured resistance (mΩ)
- T: Temperature when the resistance is measured (°C)
Calculate the difference between the maximum and minimum resistance.
Standard Resistance:

Difference is 5 mΩ or less

Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

Standard Resistance

REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY (USING MEGOHMMETER)

Tester Connection	Specified Condition
U - Body ground and shielded wire ground	10 MΩ or higher
V - Body ground and shielded wire ground	10 MΩ or higher
W - Body ground and shielded wire ground	10 MΩ or higher

NG: Go to step 13

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (MG ECU - REAR MOTOR RESOLVER)

NOTE: Be sure to wear insulated gloves.

Disconnect the I21 connector from the MG ECU.

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 - REAR MOTOR RESOLVER (VOLTAGE)

Tester Connection	Specified Condition
RRF (I21-21) - Body ground	Below 1 V
RRFG (I21-22) - Body ground	Below 1 V
RSN (I21-29) - Body ground	Below 1 V
RSNG (I21-30) - Body ground	Below 1 V
RCS (I21-11) - Body ground	Below 1 V
RCSG (I21-23) - Body ground	Below 1 V

NOTE: Turning the ignition switch to the ON position with the MG ECU connectors disconnected causes other DTCs to be stored. Clear the DTCs after performing the inspection.

Turn the ignition switch off.

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

Standard Resistance (Check for open)

MG ECU - REAR MOTOR RESOLVER (CHECK FOR OPEN)

Tester Connection	Specified Condition
RRF (I21-21) - RRFG (I21-22)	7.65 to 10.2 Ω
RSN (I21-29) - RSNG (I21-30)	12.6 to 16.8 Ω
RCS (I21-11) - RCSG (I21-23)	12.6 to 16.8 Ω

Standard Resistance (Check for short)

MG ECU - REAR MOTOR RESOLVER (CHECK FOR SHORT)

Tester Connection	Specified Condition
RRF (I21-21) or RRFG (I21-22) - Body ground	10 kΩ or higher
RSN (I21-29) or RSNG (I21-30) - Body ground	10 kΩ or higher
RCS (I21-11) or RCSG (I21-23) - Body ground	10 kΩ or higher

Fig 7: Checking Harness And Connector (MG ECU - Rear Motor Resolver)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE W/ CONVERTER INVERTER ASSEMBLY

NG: GO TO NEXT STEP

CHECK CONNECTION CONDITION OF REAR MOTOR RESOLVER CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connections of the rear motor resolver connector.
  OK:
  
  Connectors are connected securely and there is no poor connection.
Fig 8: Identifying Rear Motor Resolver Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONNECT SECURELY

OK: GO TO NEXT STEP

INSPECT REAR MOTOR RESOLVER

Disconnect the M18 rear motor resolver connector.

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

Standard Resistance

REAR MOTOR RESOLVER

Tester Connection	Specified Condition
RRF (M18-1) - RRFG (M18-4)	7.65 to 10.2 Ω
RSN (M18-2) - RSNG (M18-5)	12.6 to 16.8 Ω
RCS (M18-3) - RCSG (M18-6)	12.6 to 16.8 Ω

Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

Standard Resistance

REAR MOTOR RESOLVER (USING MEGOHMMETER)

Tester Connection	Specified Condition
RRF (M18-1) - RSN (M18-2)	10 MΩ or higher
RRF (M18-1) - RCS (M18-3)	10 MΩ or higher
RSN (M18-2) - RCS (M18-3)	10 MΩ or higher
RRFG (M18-4) - RSNG (M18-5)	10 MΩ or higher
RRFG (M18-4) - RCSG (M18-6))	10 MΩ or higher
RSNG (M18-5) - RCSG (M18-6)	10 MΩ or higher
Each terminal listed above - Transaxle housing	10 MΩ or higher

Fig 9: Inspecting Rear Motor Resolver

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK FRAME WIRE NO. 3 (W/ CONVERTER INVERTER ASSEMBLY - REAR TRACTION MOTOR)

CAUTION: Be sure to wear insulated gloves.

Check the service plug grip is removed.
Remove the frame wire No. 3 (three-phase AC cable for Rear Motor) from the rear traction motor w/ transaxle assembly.

Fig 10: Identifying Frame Wire No. 3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 11: Measuring Resistance Of Frame Wire No. 3 (W/Converter Inverter Assembly - Rear Traction Motor)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

Standard Resistance

FRAME WIRE NO. 3 (W/ CONVERTER INVERTER ASSEMBLY - REAR TRACTION MOTOR) (USING MEGOHMMETER)

Tester Connection	Specified Condition
U - Body ground and shielded wire ground	10 MΩ or higher
V - Body ground and shielded wire ground	10 MΩ or higher
W - Body ground and shielded wire ground	10 MΩ or higher

NOTE: Wrap the three-phase AC cable terminals on the w/ converter inverter assembly side with protective tape to prevent the terminals from contacting the vehicle body.

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

Standard Resistance

FRAME WIRE NO. 3 (W/ CONVERTER INVERTER ASSEMBLY - REAR TRACTION MOTOR)

Tester Connection	Specified Condition
U - U	Below 1 Ω
V - V	Below 1 Ω
W - W	Below 1 Ω

NG: REPLACE FRAME WIRE NO. 3

OK: GO TO NEXT STEP

INSPECT EXTENSION WIRE ASSEMBLY

Remove the rear traction motor w/ transaxle assembly. (See OIL PUMP ASSEMBLY )
Remove the extension wire assembly from the rear traction motor w/ transaxle assembly. (See OIL PUMP ASSEMBLY )

Using a megohmmeter, measure the insulation resistance according to the value(s) in the table below.

Standard Resistance

EXTENSION WIRE ASSEMBLY (USING MEGOHMMETER)

Tester Connection	Specified Condition
U - Shield shell	10 MΩ or higher
V - Shield shell	10 MΩ or higher
W - Shield shell	10 MΩ or higher

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

Fig 12: Inspecting Extension Wire Assembly

Standard Resistance

EXTENSION WIRE ASSEMBLY

Tester Connection	Specified Condition
U - U	Below 1 Ω
V - V	Below 1 Ω
W - W	Below 1 Ω

NG: REPLACE EXTENSION WIRE ASSEMBLY

OK: REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY