HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A78-306

DESCRIPTION

For a description of the inverter, Click here.

If the MG2 torque execution value does not correspond to the torque command value from the MG ECU to MG2, the power management control ECU (HV CPU) will store this DTC.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (HV)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the power switch on (IG).

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

   4. Check if DTCs are output.

      Result
      Result Proceed to P0A78-306 only is output. A Any of the following DTCs are also output. B

      DTC No.	Relevant Diagnosis
      P0A1A (all INF codes)*1	Generator Control Module
      P0A1B (all INF codes)*1	Drive Motor "A" Control Module
      P0A1C (all INF codes)*1	Drive Motor "B" Control Module
      P0A1D (all INF codes)*1	Hybrid Powertrain Control Module
      P0A3F-243	Drive Motor "A" Position Sensor Circuit
      P0A40-500	Drive Motor "A" Position Sensor Circuit Range/Performance
      P0A41-245	Drive Motor "A" Position Sensor Circuit Low
      P0A4B-253	Generator Position Sensor Circuit
      P0A4C-513	Generator Position Sensor Circuit Range/Performance
      P0A4D-255	Generator Position Sensor Circuit Low
      P0A60 (all INF codes)*1	Drive Motor "A" Phase V Current
      P0A63 (all INF codes)*1	Drive Motor "A" Phase W Current
      P0A69 (all INF codes)*1	Drive Motor "B" Phase V Current
      P0A6C (all INF codes)*1	Drive Motor "B" Phase W Current
      P0A72 (all INF codes)*1	Generator Phase V Current
      P0A75 (all INF codes)*1	Generator Phase W Current
      P0A78-202, 266, 267, 279, 287, 503, 504, 505, 506, 586, 806, 807, 808	Drive Motor "A" Inverter Performance
      P0A7A-203, 325, 517, 518, 809, 810, 811	Generator Inverter Performance
      P0A94-547, 548, 549, 554, 555, 556, 585, 587, 589, 590	DC/DC Converter Performance
      P0AA6 (all INF codes)*1	Hybrid Battery Voltage System Isolation Fault
      P0C76-523	Hybrid Battery System Discharge Time Too Long
      P3004-132	High Voltage Power Resource
      P3233-750	Blocking of HV Gate Connection (Circulate of Power Supply)

      Tech Tips

      
      

      • *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.

      • 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.

   5. Turn the power switch off.

   
   

   B

   GO TO DTC CHART Click here

   A

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

   CAUTION:

   Be sure to wear insulated gloves.

   
   

   1. Check that the service plug grip is not installed.

      Note

      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.

      Note

      Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector does not pull out.

      

   2. 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.

      Tech Tips

      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

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

   CAUTION:

   Be sure to wear insulated gloves.

   
   

   1. Check that the service plug grip is not installed.

      Note

      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.

   2. 

      Remove the inverter terminal cover from the inverter with converter assembly.

   3. 

      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}

      Note

      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).

   4. Check for arc marks at the bolts for the motor cable.

      Result

      Result Proceed to The terminals are connected securely and there are no contact problems. There are no arc marks. A The terminals are not connected securely and there is a contact problem. There are arc marks. B The terminals are not connected securely and there is a contact problem. There are no arc marks. C The terminals are connected securely and there are no contact problems. There are arc marks. B

   5. Install the inverter terminal cover.

   
   

   B

   REPLACE MALFUNCTIONING PARTS

   C

   CONNECT SECURELY

   A

4. CHECK HYBRID VEHICLE TRANSAXLE ASSEMBLY (MG2)

   CAUTION:

   Be sure to wear insulated gloves.

   
   

   1. Check that the service plug grip is not installed.

      Note

      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.

   2. 

      Remove the inverter terminal cover from the inverter with converter assembly.

   3. Disconnect the generator cable and motor cable from the inverter with converter assembly.

   4. 

      Text in Illustration

      *1	Motor Cable
      *2	Shield Ground

      Check MG2 for an interphase short using a milliohmmeter.

      
      

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

         Tech Tips

         If the MG2 temperature is high, the resistance will vary greatly from the specification. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

         Standard Resistance
         Tester Connection Switch Condition Specified Condition z38-3 (U) - z38-2 (V) Power switch off 52 to 60 mΩ z38-2 (V) - z38-1 (W) Power switch off 50 to 58 mΩ z38-1 (W) - z38-3 (U) Power switch off 50 to 58 mΩ

         Tech Tips

         To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68° F).

         
         

         • R20 = Rt / {1 + 0.00393 X (T - 20)}

         The calculation is based on the following:

         
         

         • R20: Resistance at 20°C (68° F) (mΩ)

         • Rt: Measured resistance (mΩ)

         • T: Temperature when the resistance is measured (° C)

   5. Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

      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
      Tester Connection Switch Condition Specified Condition z38-3 (U) - Body ground and shield ground Power switch off 100 MΩ or higher z38-2 (V) - Body ground and shield ground Power switch off 100 MΩ or higher z38-1 (W) - Body ground and shield ground Power switch off 100 MΩ or higher

   6. Connect the generator cable and motor cable.

   7. Install the inverter terminal cover.

   
   

   NG

   REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Click here

   OK

   REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here