| DTC Code | DTC Name |
|---|---|
| P0A78-505 | Drive Motor "A" Inverter Performance |
| P0A78-806 | Drive Motor "A" Inverter Performance |
DESCRIPTION
For a description of the inverter Click here.
If the motor inverter overheats, has a circuit malfunction, or has an internal short, the inverter transmits this information to the MG ECU via the motor inverter fail signal line. If an abnormal amount of current flows through the motor inverter, the MG ECU detects it and sends a signal to inform the power management control ECU of the malfunction.
Tech Tips
The term "drive motor A" indicates motor (MG2).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0A78-505 | Motor inverter fail signal detection (overcurrent due to MG ECU malfunction)* (1 trip detection logic) |
Inverter with converter assembly |
| P0A78-806 | Abnormal motor (MG2) current value detection (MG ECU malfunction)* (1 trip detection logic) |
*: The MG ECU, which is built into the inverter with converter assembly, is suspected to be the main cause of the malfunction.
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 removing 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 Click here.
Tech Tips
Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
Note
After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.
Tech Tips
After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
Turn the power switch on (READY) and wait for 5 seconds or more.
Perform a road test according to the freeze frame data and item "Vehicle Spd" for approximately 10 minutes.
PROCEDURE
CHECK DTC OUTPUT (HYBRID CONTROL)
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
Check for DTCs.
| Result | Proceed to |
|---|---|
| P0A78-202 is not output. | A |
| P0A78-202 is also output. | B |
Note
If P0A78-202 is output, troubleshoot it first. After completing the troubleshooting for P0A78-202, perform troubleshooting for this DTC.
Parts repaired or replaced during troubleshooting for P0A78-202 do not need to be re-inspected in this diagnosis procedure.
Turn the power switch off.
| B |
|
GO TO DTC CHART (P0A78-202) Click here |
| A |
|
CHECK DTC OUTPUT (HYBRID CONTROL)
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
Check for DTCs.
Tech Tips
If P0A78-202 was not output in step 1 of this diagnosis procedure, check Table 1 below.
If P0A78-202 was output in step 1 of this diagnosis procedure, diagnose that DTC first, then check Table 2 below.
| Result | Proceed to |
|---|---|
| P0A78-505 or 806 only is output, or DTCs except the ones in the tables below are also output. | A |
| Any of the following DTCs are also output. | B |
| Relevant DTC | |
|---|---|
| P0A1A (all INF codes)*1 | Generator Control Module |
| P0A1B (all INF codes)*1 | Drive Motor "A" 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 |
| P0A72 (all INF codes)*1 | Generator Phase V Current |
| P0A75 (all INF codes)*1 | Generator Phase W Current |
| P0A78-266, 267, 586 | Drive Motor "A" Inverter Performance |
| P0A94-585, 587, 589, 590 | DC / DC Converter Performance |
| P0C76-523 | Hybrid Battery System Discharge Time Too Long |
| Relevant DTC | |
|---|---|
| P0A1A (all INF codes)*1 | Generator Control Module |
| P0A1B (all INF codes)*1 | Drive Motor "A" 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 |
| P0A60-294 | Drive Motor "A" Phase V Current |
| P0A63-302 | Drive Motor "A" Phase W Current |
| P0A72 (all INF codes)*1 | Generator Phase V Current |
| P0A75 (all INF codes)*1 | Generator Phase W Current |
| P0A78-266, 267, 586 | Drive Motor "A" Inverter Performance |
| P0A94-585, 587, 589, 590 | DC / DC Converter Performance |
| P0C76-523 | Hybrid Battery System Discharge Time Too Long |
Tech Tips
*1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.
P0A78-505 or P0A78-806 may be stored due to a malfunction which also causes DTCs in the preceding tables to be stored. In this case, first troubleshoot the output DTCs in the preceding tables. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.
Turn the power switch off.
| B |
|
GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here |
| A |
|
REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here