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Home >> Lexus >> 2012 >> LS 600h V8-5.0L (2UR-FSE) Hybrid >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0A78 >> P0A78-306

P0A78-306





L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-306: Drive Motor "A" Inverter Performance
P0A78-306 - Drive Motor "A" Inverter Performance

DESCRIPTION

For a description of the inverter, P0A78-266.

If the MG2 torque execution value does not correspond to the torque command value from the MG ECU to MG2, the hybrid vehicle control ECU will store this DTC.

HINT
The term "drive motor A" refers to MG2.





MONITOR DESCRIPTION

If the difference between the requested MG2 torque and the actual MG2 torque exceeds a predetermined value, the MG ECU determines that there is a malfunction in the execution or monitoring of MG2 torque. Then, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the power switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the power switch off.

5. Turn the power switch on (READY) and turn the Techstream on.

6. Slowly accelerate from a stop (0 km/h (0 mph)) to 40 km/h (25 mph) several times while using different acceleration patterns.

7. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

8. Check that the permanent DTCs are cleared.

9. If the permanent DTCs are not cleared, perform the universal trip, and then check for permanent DTCs again.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

INSPECTION PROCEDURE

CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT (HV)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

(d) Check if DTCs are output.

Result:









HINT
- *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic flowchart.
- P0A78-306 may be set due to a malfunction which also causes DTCs in the preceding table to be set. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

B -- GO TO DTC CHART Hybrid Control System
A -- Continue to next step.

2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

NOTICE:
Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector cannot be pulled out.

(a) Check the connection of the low voltage connector of the inverter with converter assembly.

OK:

The connector is connected securely and there are no contact problems.

HINT
When connecting the connector, insert it with the locking lever in the raised position. Rotate the lever downward and make sure that the connector is pulled into its socket. When the locking lever is in its fully closed position, a click will be heard as its locking claws engage. After the click is heard, pull up on the connector to confirm that it is properly connected.

NG -- CONNECT SECURELY
OK -- Continue to next step.

3. CHECK INVERTER WITH CONVERTER ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

CAUTION:
Be sure to wear insulated gloves.

(a) Turn the power switch off.

(b) Remove the service plug grip Hybrid Control System.

NOTICE:
After removing the service plug grip, do not turn the power switch on (READY) unless instructed by the repair manual because this may cause a malfunction.

(c) Remove the inverter terminal cover from the inverter with converter assembly Removal.

NOTICE:
Lift the inverter terminal cover horizontally so that it does not tilt. Failure to do so may break the inverter cover guide pins.





(d) Check that the bolts for the motor cable are tightened to the specified torque, the motor cable is connected securely, and there are no contact problems.





Specified Condition:

T=8.0 N*m {82 kgf*cm, 71 in.*lbf}

NOTICE:
Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

(e) Check for arc marks at the bolts for the motor cable.

Result:





B -- REPLACE MALFUNCTIONING PARTS

C -- CONNECT SECURELY
A -- Continue to next step.

4. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MG2) P0A78-128

NG -- CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)

OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Installation

5. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MOTOR CABLE CONNECTION CONDITION) P0A78-128

B -- REPLACE MALFUNCTIONING PARTS

C -- CONNECT SECURELY
A -- Continue to next step.

6. CHECK MOTOR CABLE P0A78-128

NG -- REPLACE MOTOR CABLE Components

OK -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY Components
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