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 DTC. (See DTC CHECK / CLEAR )

Result:

The DTCs shown in the table below are output

OUTPUT DTC (HV)

DTC No.	Relevant Diagnosis
P0A1A (all details), P0A1B (all details), P0A1C (all details)	MG ECU circuit malfunction
P0A1D (all details)	HV ECU circuit malfunction
P0A3F-243, P0A40-500, P0A41-245	Motor resolver circuit malfunction
P0A45-669, P0A46-271, P0A47-670	Rear motor resolver circuit malfunction
P0A4B-253, P0A4C-513, P0A4D-255	Generator resolver circuit malfunction
P0A93-147, P0A93-347, P0A05-776	MG ECU circuit malfunction
P0A60 (all details), P0A63 (all details)	Motor current sensor circuit
P0A69 (all details), P0A6C (all details)	Rear motor current sensor circuit
P0A72 (all details), P0A75 (all details)	Generator current sensor circuit
P0A78-510, 508, 586, 266, 272, 280, 304, 267, 278, 283, 285, 305, 523	Motor inverter function malfunction
P0A79-703, 701, 672, 690, 691, 697, 698	Rear motor inverter function malfunction
P0A7A-522, 520, 309, 321, 323, 342, 343	Generator inverter function malfunction
P0A94-585, 587, 561, 551, 588, 589, 545, 546, 552, 558, 559, 583, 584, 590	Boost converter circuit
P0AA6 (all details)	High-voltage system insulation malfunction
P3004-132	High-voltage system
P3232-749, P3233-750	HV gate shutdown wiring 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.
P0A79-704 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 REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY
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. Check that the bolts for the three-phase AC cable of the rear traction motor w/ transaxle assembly are tightened to the specified torque.
  Torque: 15 N*m (153 kgf*cm, 11 ft.*lbf)
  
  Fig 1: Identifying Rear Traction Motor W/Transaxle Assembly Bolts
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: TIGHTEN THEM TO SPECIFIED TORQUE

OK: GO TO NEXT STEP
CHECK CONNECTION CONDITION OF MG ECU CONNECTOR (LOOSENESS AND POOR CONTACT)
CAUTION: Be sure to wear insulated gloves.
1. Check that the service plug grip is removed.
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.
  Result:
  
  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
CHECK W/ CONVERTER INVERTER ASSEMBLY (REAR MOTOR)
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 of the rear traction motor w/ transaxle assembly are tightened to the specified torque.
  Torque: 10 N*m (102 kgf*cm, 7 ft.*lbf)
  
  Fig 3: Checking Bolts For Three-Phase AC Cable
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: TIGHTEN THEM TO SPECIFIED TORQUE

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 for Rear Motor from the inverter.

Fig 4: 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.

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)

Fig 5: Inspecting Rear Traction Motor W/Transaxle Assembly

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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 8

OK: GO TO NEXT STEP

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

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Disconnect the three-phase AC cable for Rear Motor from the rear traction motor w/ transaxle assembly.

Fig 6: Identifying Frame Wire No. 3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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) VOLTAGE

Tester Connection (Rear traction motor w/ transaxle assembly side - w/converter inverter assembly side)	Specified Condition
U - U	Below 1 Ω
V - V	Below 1 Ω
W - W	Below 1 Ω

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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.

Standard Resistance

EXTENSION WIRE ASSEMBLY

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

Fig 8: Inspecting Extension Wire Assembly

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE EXTENSION WIRE ASSEMBLY

OK: REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY

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

CAUTION: Be sure to wear insulated gloves.

Check that the service plug grip is removed.
Disconnect the three-phase AC cable from the rear motor.
NOTE: Wrap the terminals of disconnected cable with protective tape to prevent the terminals from contacting the vehicle body.

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)

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

Fig 9: Identifying Three-Phase AC Cable For Rear Motor (W/ Converter Inverter Assembly Side And Rear Traction W/Transaxle Assembly Side)

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.

Standard Resistance

EXTENSION WIRE ASSEMBLY

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

Fig 10: Inspecting Extension Wire Assembly

NG: REPLACE EXTENSION WIRE ASSEMBLY

OK: REPLACE REAR TRACTION MOTOR W/TRANSAXLE ASSEMBLY