P0A94 / INF557

DTC P0A94-557 DC / DC Converter Performance

DESCRIPTION

DTC Detection Condition:

The boost converter boosts the 288 V DC from the HV battery to a maximum of approximately 650 V DC. The inverter converts the voltage that has been boosted by the boost converter into alternating current, which is used for driving MG2 and MG1. When MG1 and MG2 operate as a generator, the alternating-current voltage from MG1 and MG2 is converted into direct-current voltage by the inverter. Then the boost converter drops this voltage to a direct-current voltage rating of 288 V in order to charge the HV battery.

The MG ECU uses a voltage sensor (VL) that is built into the boost converter to detect the high voltage before it is boosted. It also uses a voltage sensor (VH) that is built into the inverter to detect the high voltage after it is boosted. Based on the voltage before and after it is boosted, the hybrid vehicle control ECU controls the operation of the boost converter to boost the voltage to the target voltage.

If the boost converter detects a circuit malfunction, overheat, or internal short, it transmits this information to the FCV terminal of the MG ECU via the boost converter fail signal line.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

If the boost converter detects a circuit malfunction, it transmits a boost converter fail signal to the MG ECU. Upon receiving this signal, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

Step 1:

Step 1(Continued)-4:

Step 4(Continued)-6:

Step 6(Continued)-8:

Step 9-10:

Step 11-13:

Step 14-15:

Step 15(Continued)-16:

Step 17-18:

Step 18(Continued)-20:

Step 21-22:

Step 22(Continued)-23:

Step 24:

Step 25-26:

Step 26(Continued)-28:

Step 28(Continued)-29:

Step 29(Continued)-31:

Step 31(Continued):

Step 32-33:

Step 33(Continued)-34:

Step 35-37:

Step 37(Continued):

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 disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting, check the voltage at the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

NOTE: If the water pump with motor bracket assembly is the final part to be replaced after performing the inspection procedure, be sure to inspect the INV W/P fuse for continuity. If there is no continuity, replace the water pump with motor bracket assembly and the INV W/P fuse.

HINT:
- Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.
- After inspection, be sure to replace the inverter with converter assembly.