Refer to the wiring diagram for DTC P0A78-118 Click here.
|DTC No.||INF Code||DTC Detection Condition||Trouble Area|
|P0A78||503||Motor inverter overvoltage signal detection (overvoltage due to MG ECU malfunction)||Inverter with converter assembly|
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.
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
CHECK DTC OUTPUT (HV)
Connect the intelligent tester to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
Check if DTCs are output.
|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|
|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|
|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|
|P0A45-669||Drive Motor "B" Position Sensor Circuit|
|P0A46-671||Drive Motor "B" Position Sensor Circuit Range/Performance|
|P0A47-670||Drive Motor "B" 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|
|P0A78-266, 267, 287, 505, 506, 586, 806, 807, 808||Drive Motor "A" Inverter Performance|
|P0A79-693, 694, 695, 812, 813, 814||Drive Motor "B" Inverter Performance|
|P0A7A-325, 517, 518, 809, 810, 811||Generator Inverter Performance|
|P0A93-346||Inverter Cooling System Performance|
|P0A94-169, 170, 171, 554, 555, 556, 585, 587, 589, 590||DC/DC Converter Performance|
|P0ADB-227||Hybrid Battery Positive Contactor Control Circuit Low|
|P0ADC-226||Hybrid Battery Positive Contactor Control Circuit High|
|P0ADF-229||Hybrid Battery Negative Contactor Control Circuit Low|
|P0AE0-228||Hybrid Battery Negative Contactor Control Circuit High|
|P0C73-776||Motor Electronics Coolant Pump "A" Control Performance|
|P0C76-523||Hybrid Battery System Discharge Time Too Long|
|P3004-803||High Voltage Power Resource|
|P314A-828||Inverter Coolant Pump Speed Signal|
*1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.
P0A78-503 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.
Turn the power switch off.
GO TO DTC CHART Click here
CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)
Be sure to wear insulated gloves.
Check that the service plug grip is not installed.
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.
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.
Check the connection of the low voltage connector of the inverter with converter assembly.
|The connector is connected securely and there are no contact problems.|
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.