P0A08-264

P311 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A08-264: DC / DC Converter Status Circuit

DTC P0A08-264 - DC / DC Converter Status Circuit

DESCRIPTION

The hybrid vehicle converter (DC/DC converter) converts the DC 244.8 V of the HV battery into DC 12 V in order to supply power to areas such as the vehicle's lighting, audio, and ECU systems. In addition, it charges the auxiliary battery.
A transistor bridge circuit initially converts DC 244.8 V into alternating current, and a transformer lowers its voltage. Then, it is rectified and smoothed (into DC) and converted into DC 12 V.
The hybrid vehicle converter (DC/DC converter) controls the output voltage in order to keep a constant voltage at the terminals of the auxiliary battery.





The hybrid vehicle control ECU uses the NODD signal line to transmit a stop command to the hybrid vehicle converter (DC/DC converter) and receive signals indicating the normal or abnormal condition of the 12 V charging system.
If the vehicle is being driven with an inoperative hybrid vehicle converter (DC/DC converter), the voltage of the auxiliary battery will drop, which will prevent the continued operation of the vehicle. Therefore, the hybrid vehicle control ECU monitors the operation of the hybrid vehicle converter (DC/DC converter) and alerts the driver if it detects a malfunction.






WIRING DIAGRAM





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 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.
HINT: Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK DTC OUTPUT
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:





HINT:
- Turning the power switch on (IG) with the service plug grip and inverter cover removed causes interlock switch system DTC P0A0D-350 to be output.
- P0A08-264 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.

YES -- GO TO DTC CHART
NO -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR) P0343
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. CHECK CONNECTOR CONNECTION CONDITION (BATTERY PACK WIRE CONNECTOR) P0A09
NG -- CONNECT SECURELY
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (RESISTANCE VALUE OF NODD INSIDE HYBRID VEHICLE CONTROL ECU)




(a) Disconnect the On1 battery pack wire connector Components.




(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BATTERY PACK WIRE CONNECTOR)
OK -- Continue to next step.
5. CHECK CONNECTOR CONNECTION CONDITION (HV RELAY ASSEMBLY CONNECTOR)
CAUTION: Be sure to wear insulated gloves.




(a) Turn the power switch off and remove the service plug grip Hybrid Control System.
NOTICE: 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.
(b) Check the connections of the HV relay assembly connectors.
Result:
The connectors are connected securely and there are no contact problems.
HINT: For the removal procedure of the HV relay assembly connector, Components.

NG -- CONNECT SECURELY
OK -- Continue to next step.
6. CHECK HV RELAY ASSEMBLY (HIGH VOLTAGE FUSE)
CAUTION: Be sure to wear insulated gloves.




(a) Check that the service plug grip is not installed.
(b) Remove the HV relay assembly Components.
(c) Measure the resistance according the the value(s) in the table below.
Standard resistance:






NG -- REPLACE HIGH VOLTAGE FUSE
OK -- Continue to next step.
7. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONVERTER CONNECTOR) P0A09
NG -- CONNECT SECURELY
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (BATTERY PACK WIRE CONNECTOR - HYBRID VEHICLE CONVERTER)
CAUTION: Be sure to wear insulated gloves.




(a) Check that the service plug grip is not installed.
(b) Disconnect the n4 hybrid vehicle converter connector (DC/DC converter) Components.
(c) Turn the power switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.





Standard voltage:





NOTICE: Turning the power switch on (IG) with the hybrid vehicle converter connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(e) Turn the power switch off.
(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for short):






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT HYBRID VEHICLE CONVERTER




(a) Connect all the disconnected connectors.
(b) Install the service plug grip.
(c) Measure the current output from the hybrid vehicle converter (DC/DC converter) with the headlight position switch and blower motor switch in the HI position, and the rear window defogger turned on (*1).
(d) Measure the auxiliary battery voltage according to the previous conditions (*1).
Result:






NG -- REPLACE HYBRID VEHICLE CONVERTER
OK -- Continue to next step.
10. CHECK FOR INTERMITTENT PROBLEMS
(a) Check for intermittent problems Hybrid Control System.
YES -- REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA
NO -- REPLACE HYBRID VEHICLE CONVERTER
11. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BATTERY PACK WIRE CONNECTOR)
(a) Disconnect the A61 hybrid vehicle control ECU connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.





Standard voltage:





NOTICE: Turning the power switch on (IG) with the hybrid vehicle control ECU connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.
(d) Turn the power switch off.
(e) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for short):






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE CONTROL ECU