P0A78-506

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-287: Drive Motor "A" Inverter Performance

DTC P0A78-287 - Drive Motor "A" Inverter Performance

DTC P0A78-505 - Drive Motor "A" Inverter Performance

DTC P0A78-506 - Drive Motor "A" Inverter Performance

DESCRIPTION

The inverter converts the high-voltage direct current of the HV battery and the alternating current for the MG1/MG2. The inverter contains a three-phase bridge circuit, which consists of 6 power transistors each for the MG1 and the MG2, in order to convert the direct current and the three-phase alternating current. The HV control ECU controls the actuation of the power transistors.
The inverter transmits information that is necessary for effecting control, such as the amperage and voltage, to the HV control ECU.

The HV control ECU uses a voltage sensor, which has been built into the inverter, to detect the high voltage after boost control.

The inverter voltage sensor outputs a voltage that varies between 0 and 5 V in accordance with the changes in the high voltage. The higher the high voltage, the higher the output voltage, and the lower the high voltage, the lower the output voltage.
The HV control ECU monitors the inverter voltage and detects a malfunction.

If the motor inverter has a circuit malfunction, internal short, or overheats, the inverter transmits that information to the MFIV terminal of the HV control ECU via the motor inverter fail signal line.

MONITOR DESCRIPTION

If over-amperage flows through the motor inverter due to an internal short, the motor inverter transmits an inverter fail signal to the HV control ECU. Upon receiving this signal, the HV control ECU illuminates the MIL and sets a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

WIRING DIAGRAM

INSPECTION PROCEDURE
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 servicing 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 are required to discharge the high-voltage condenser inside the inverter.
- When measuring insulation resistance using a megohmmeter, set the megohmmeter to 500 V.

PROCEDURE

1. READ OUTPUT DTC (HV ECU)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:
DTCs listed in the table below are output

YES -- GO TO DTC CHART. FIND THE APPLICABLE DIAGNOSTIC TROUBLE CODE TEST TO PROCEED TO DIAGNOSTIC TROUBLESHOOTING FLOWCHART
NO -- Continue to next step.

2. CHECK CONNECTION CONDITION OF HYBRID VEHICLE CONTROL ECU CONNECTOR (LOOSENESS AND POOR CONTACT)

(a) Check the connection condition of all the connectors at the HV control ECU.
OK:
Connectors have been connected securely and there is no poor connection.
NG -- CONNECT SECURELY
OK -- Continue to next step.

3. CHECK CONNECTION CONDITION OF INVERTER CONNECTOR (LOOSENESS AND POOR CONTACT)
CAUTION: Wear insulated gloves before performing the following operation.
(a) Turn the power switch OFF.
(b) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(c) Remove the inverter cover Removal.

(d) Check the connection condition of the I9 and I10 inverter connectors.
OK:
Connectors have been connected securely and there is no poor connection.
NG -- CONNECT SECURELY
OK -- Continue to next step.

4. CHECK HYBRID VEHICLE MOTOR ASSEMBLY
CAUTION: Wear insulated gloves before performing the following operation.
(a) Check that the service plug grip and inverter cover have been removed.

(b) Check if the three-phase alternating current cable installation bolts on the hybrid vehicle motor are tightened to the specified torque.
Torque: 8.0 Nm (82 kgf-cm, 71 in-lbf)
(c) Reinstall the inverter cover Installation.
(d) Reinstall the service plug grip Installation.
NG -- TIGHTEN THEM TO SPECIFIED TORQUE
OK -- Continue to next step.

5. CONFIRM INFORMATION (EXCLUSIVE INFO 4)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG).
HINT: DTCs for the interlock switch system are output when turning the power switch ON (IG) with both service plug grip and inverter cover removed.
(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
(d) Select DTC P0A78 to display its freeze frame data.
(e) Select the item that has INF code 287, 505, or 506 from among "Detail Code 1 to 5, Detail Information 1 to 5" and press ENTER.
(f) Read "Exclusive Information 4".
Result:

D -- REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY
C -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
B -- REPLACE HYBRID VEHICLE CONTROL ECU
A -- Continue to next step.

6. INSPECT HYBRID VEHICLE MOTOR ASSEMBLY
CAUTION: Wear insulated gloves before performing the following operation.
(a) Turn the power switch OFF.
(b) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(c) Remove the inverter cover Removal.

(d) Disconnect the three-phase alternating current cable for the hybrid vehicle motor from the inverter.
(e) Using a milliohm meter, measure the resistance between the three-phase alternating current cable terminals of the hybrid vehicle motor.
NOTE: If the motor temperature is too high, the resistance varies considerably, which hinders determining malfunction. Therefore, measure the resistance at a minimum 8 hours after the vehicle has been stopped.

Standard resistance:

- *: Apply the formula given below to correct the resistance.
- R20 = Rt / {(1 + 0.00393 x (T - 20)}
- Rt: Resistance between measured lines (mOhms)
- R20: Resistance converted to 68°F (20°C) (mOhms)
- T: Ambient air temperature during measurement (°F)
(f) Calculate the difference between the maximum and minimum resistance between terminals U - V, V - W, and W - U.
Standard resistance:
Below 2 mOhms
(g) Using a megohmmeter set to 500 V, measure the insulation resistance between the three-phase alternating current cable terminals of the hybrid vehicle motor and the body ground.
NOTE: Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard resistance:

(h) Reconnect the three-phase alternating current cable for the hybrid vehicle motor.
NG -- REPLACE HYBRID VEHICLE MOTOR ASSEMBLY
OK -- Continue to next step.

7. PERFORM ACTIVE TEST USING THE TECHSTREAM (FORCIBLE STOP OF INVERTER DRIVE)
CAUTION: Wear insulated gloves before performing the following operation.
(a) Reinstall the inverter cover Installation.
(b) Reinstall the service plug grip Installation.
(c) Connect the Techstream to the DLC3.
(d) Clear the DTC(s) Hybrid Control System.
HINT: Clear DTCs before inspection because the active test cannot be performed while DTCs are stored.
(e) Turn the power switch ON (IG).
(f) Turn the Techstream ON.
(g) Enter the following menus: Powertrain / Hybrid Control / Active Test.
(h) Perform the "Forcible Stop of Inverter Drive".
(i) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(j) Remove the inverter cover Removal.

(k) Measure the voltage between the terminals of the inverter connector while performing "Forcible Stop of Inverter Drive".
Standard voltage:

(l) Turn the power switch OFF.
(m) Reinstall the inverter cover Installation.
(n) Reinstall the service plug grip Installation.
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
NG -- Continue to next step.

8. PERFORM ACTIVE TEST USING THE TECHSTREAM (FORCIBLE STOP OF INVERTER DRIVE)
CAUTION: Wear insulated gloves before performing the following operation.
(a) Connect the Techstream to the DLC3.
(b) Clear the DTC(s) Hybrid Control System.
HINT: Clear DTCs before inspection because the active test cannot be performed while DTCs are stored.
(c) Turn the power switch ON (IG).
(d) Turn the Techstream ON.
(e) Enter the following menus: Powertrain / Hybrid Control / Active Test.
(f) Perform the "Forcible Stop of Inverter Drive".
(g) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(h) Remove the inverter cover Removal.

(i) Disconnect the I10 inverter connector.
(j) Measure the voltage between the terminals of the inverter connector while performing "Forcible Stop of Inverter Drive".
Standard voltage:

(k) Turn the power switch OFF.
(l) Reconnect the inverter connector.
(m) Reinstall the inverter cover Installation.
(n) Reinstall the service plug grip Installation.
NG -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
OK -- Continue to next step.

9. INSPECT INVERTER WITH CONVERTER ASSEMBLY
CAUTION: Wear insulated gloves before performing the following operation.
(a) Check that the service plug grip and inverter cover have been removed.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause a malfunction. Therefore, never turn the power switch ON (READY) in this state.

(b) Disconnect the frame wire from the inverter.

(d) Measure the resistance between the three-phase alternating current cable terminals and the inverter terminals labeled A and B in the illustration.
HINT: Each measurement needs to be performed 2 times. The polarity of the tester probes needs to be switched for the second measurement.

Standard resistance:

HINT: This measurement is an inspection of the diodes in the inverter.
(e) Reconnect the three-phase alternating current cable for the hybrid vehicle motor.
(f) Reinstall the inverter cover Installation.
(g) Reconnect the frame wire from the inverter.
(h) Reinstall the service plug grip Installation.
NG -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
OK -- REPLACE HYBRID VEHICLE CONTROL ECU