P0A94-588

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A94-588: DC / DC Converter Performance

DTC P0A94-588 - DC / DC Converter Performance

DESCRIPTION

The boost converter contains a booster IPM (Intelligent Power Module), which includes an IGBT (Insulated Gate Bipolar Transistor) and a reactor. The HV control ECU actuates the IGBT, which controls the current in the reactor.
The boost converter boosts the high-voltage direct current rated at 201.6 V to an approximate direct current voltage of 500 V. The inverter converts the voltage that has been boosted by the boost converter into alternating current, which is used for driving the MG1/MG2. When the MG1/MG2 operates as a generator, the alternating current of approximately 500 V from the MG1/MG2 is converted into direct current by the inverter.
Then, the boost converter drops this voltage to a direct current voltage rated at 201.6 V in order to charge the HV battery.

The HV control ECU uses a voltage sensor that is built into the boost converter to detect the high voltage (VL) before it is boosted. Also, it uses a voltage sensor that is built into the inverter to detect the high voltage (VH) after it has been boosted.
Based on the voltage before and after it has been boosted, the HV control ECU boosts it to a target voltage by controlling the operation of the boost converter.

The boost converter switches the power transistors ON and OFF in accordance with the power transistor actuation signals received from the HV control ECU, in order to change the current that flows into the reactor.
Also, the boost converter regulates the duration of the switching time through PWM (Pulse Width Modulation) control, in order to control the boosting voltage.
The HV control ECU monitors the boost converter PWM circuit and detects a malfunction.

MONITOR DESCRIPTION

The HV control ECU monitors the boost converter PWM circuit. If there is an error in the power transistor actuation signals which are transmitted to the boost converter, the HV control ECU interprets this as a malfunction of the boost converter PWM circuit.
The HV control ECU illuminates the MIL and sets a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

WIRING DIAGRAM

INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are servicing the high-voltage system.
- After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.
HINT: At least 5 minutes are required to discharge the high-voltage condenser inside the inverter.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)
CAUTION: Wear insulated gloves before performing the following operation.
(a) Turn the power switch OFF.
(b) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.

(e) Disconnect the I10 inverter connector.
(f) Turn the power switch ON (IG).
HINT: DTCs for the interlock switch system are output when turning the power switch ON (IG) with both service plug grip and inverter cover removed.
(g) Measure the voltage between the terminal of the HV control ECU connector and body ground.
Standard voltage:

(h) Turn the power switch OFF.
(i) Measure the resistance between the wire harness side connectors.
Standard resistance (Check for open):

Standard resistance (Check for short)

(j) Reconnect the inverter connector.
(k) Reconnect the HV control ECU connector.
(l) Reinstall the inverter cover Installation.
(m) Reinstall the service plug grip Installation.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY