P0C76

HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM: P0C76-523: Hybrid Battery System Discharge Time Too Long
P0C76-523 - Hybrid Battery System Discharge Time Too Long

DESCRIPTION

The inverter contains a three-phase bridge circuit, which consists of six power transistors (IGBTs) each for MG1 and MG2. The inverter converts high-voltage direct current from the HV battery into three-phase alternating current for MG1 and MG2; it also converts three-phase alternating current supplied by MG1 and MG2 into direct current for the HV battery. The MG ECU controls the actuation of the power transistors (IGBTs). The inverter transmits information necessary for control, such as amperage and voltage, to the MG ECU.





The MG ECU uses a voltage sensor, which is built into the inverter, to detect boosted high voltage (VH) to allow control of the voltage boost.

The inverter voltage sensor outputs voltage that varies between 0 and 5 V in accordance with the changes in the boosted voltage. The higher the boosted voltage, the higher the sensor output voltage, and the lower the boosted voltage, the lower the sensor output voltage.

The MG ECU monitors the inverter voltage and detects malfunctions.





HINT
When the power switch is turned off, the MG ECU applies current to MG2 in a way that does not generate torque, in order to discharge the residual voltage in the inverter. When the hybrid system is normal, the VH value is almost 0 V after discharge. This DTC will be stored if the VH value is more than the specified value after discharge.





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (HV)

(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:









HINT
P0C76-523 may be output due to a malfunction which causes the DTCs in the table above to be output. In this case, first troubleshoot the output DTCs in the table above. Then, perform a reproduction test to check that no DTCs are output.

(e) Turn the power switch off.

B -- GO TO DTC CHART Hybrid Control System

A -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Components