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 (Except for 287, 505, 806, 807, and 808)	Motor inverter function malfunction
P0A7A	Generator inverter function malfunction
P0A90	Motor function malfunction
P0A92	Generator function malfunction
P0A94 (Except for 554 and 555)	Boost converter circuit
P0AA1, P0AA2, P0AA4, P0AA5	System main relay circuit
P0AA6, P3004	High-voltage system
P0A79	Rear motor inverter function malfunction
P0A45, P0A46, P0A47	Rear motor resolver malfunction
P0A69, P0A6C, P0A55	Rear motor current sensor circuit
P0A1A, P0A1B, P0A1C	MG ECU malfunction

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.
P0A78-287 and P0A78-505 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 CONNECTION CONDITION OF HV CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connections of the HV control ECU connectors.
  OK:
  
  Connectors are connected securely and there is no poor connection.
Fig 1: Checking Connection Condition Of HV 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 2: 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 W/ CONVERTER INVERTER ASSEMBLY
CAUTION: Be sure to wear insulated gloves.
1. Check that the service plug grip is removed.
2. Check that the bolts for the three-phase AC cable for Motor are tightened to the specified torque.
  Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf)
Fig 3: Checking W/Converter Inverter Assembly Bolts
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: TIGHTEN THEM TO SPECIFIED TORQUE

OK: GO TO NEXT STEP

INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR)

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Disconnect the three-phase AC cable of the HV Motor from the w/ converter inverter assembly.
Move the shift lever to the N position and lift up the vehicle.

Fig 4: Identifying Three-Phase AC Cable Of HV Motor
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 5: Identifying Three-Phase AC Cable Of HV Motor (Shielded Wire Ground)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR) (USING MILLIOHMMETER)

Tester Connection	Specified Condition
U - V	48 to 59mΩ or less (20°C)
V - W	48 to 59mΩ or less (20°C)
W - U	48 to 59mΩ or less (20°C)

NOTE: If the Motor temperature is too high, the resistance varies 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

HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR) (USING MEGOHMMETER)

Tester Connection	Specified Condition
Three-phase AC Cable for Motor U terminal - Body ground and Shielded wire ground	10 MΩ or higher
Three-phase AC Cable for Motor V terminal - Body ground and Shielded wire ground	10 MΩ or higher
Three-phase AC Cable for Motor W terminal - Body ground and Shielded wire ground	10 MΩ or higher

NG: REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

OK: GO TO NEXT STEP

CHECK HARNESS AND CONNECTOR (MG ECU - MOTOR RESOLVER)

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Disconnect the I22 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 - MOTOR RESOLVER

Tester Connection	Specified Condition
MRF (I22-13) - Body ground	Below 1 V
MRFG (I22-23) - Body ground	Below 1 V
MSN (I22-21) - Body ground	Below 1 V
MSNG (I22-20) - Body ground	Below 1V
MCS (I22-19) - Body ground	Below 1 V
MCSG (I22-18) - Body ground	Below 1 V

Fig 6: Checking Harness And Connector (MG ECU - Motor Resolver)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

MG ECU - MOTOR RESOLVER (OFF POSITION) (1 OF 2)

Tester Connection	Specified Condition
MRF (I22-13) - MRFG (I22-23)	7.65 to 10.2 Ω
MSN (I22-21) - MSNG (I22-20)	12.6 to 16.8 Ω
MCS (I22-19) - MCSG (I22-18)	12.6 to 16.8 Ω

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

Standard Resistance

MG ECU - MOTOR RESOLVER (OFF POSITION) (2 OF 2)

Tester Connection	Specified Condition
MRF (I22-13) or MRFG (I22-23) - Body ground	10 kΩ or higher
MSN (I22-21) or MSNG (I22-20) - Body ground	10 kΩ or higher
MCS (I22-19) or MCSG (I22-18) - Body ground	10 kΩ or higher

NG: REPLACE W/ CONVERTER INVERTER ASSEMBLY

OK: GO TO NEXT STEP

CHECK CONNECTION CONDITION OF MOTOR RESOLVER CONNECTOR (LOOSENESS AND POOR CONTACT)
1. Check the connection of the motor resolver connector.
  OK:
  
  Connector is connected securely and there is no poor connection.
Fig 7: Checking Connection Condition Of Motor Resolver Connector (Looseness And Poor Contact)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: CONNECT SECURELY

NG: GO TO NEXT STEP

INSPECT MOTOR RESOLVER

Disconnect the M14 motor resolver connector.

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

Standard Resistance

MOTOR RESOLVER

Tester Connection	Specified Condition
MRF (M14-1) - MRFG (M14-4)	7.65 to 10.2 Ω
MSN (M14-2) - MSNG (M14-5)	12.6 to 16.8 Ω
MCS (M14-3) - MCSG (M14-6)	12.6 to 16.8 Ω

Fig 8: Inspecting Motor Resolver

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

Standard Resistance

MOTOR RESOLVER (USING MEGOHMMETER)

Tester Connection	Specified Condition
MRF (M14-1) - MSN (M14-2)	10 MΩ or higher
MRF (M14-1) - MCS (M14-3)	10 MΩ or higher
MSN (M14-2) - MCS (M14-3)	10 MΩ or higher
MRFG (M14-4) - MSNG (M14-5)	10 MΩ or higher
MRFG (M14-4) - MCSG (M14-6)	10 MΩ or higher
MSNG (M14-5) - MCSG (M14-6)	10 MΩ or higher
Each terminal listed above - Transaxle housing	10 MΩ or higher

NG: REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR