P0A1B-788

P310 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A1B-788: Drive Motor "A" Control Module

DTC P0A1B-788 - Drive Motor "A" Control Module

DESCRIPTION

If the MG ECU is reset due to an auxiliary battery voltage drop or abnormality, the hybrid vehicle control ECU will set this DTC.
HINT: The term "drive motor A" indicates MG2.





MONITOR DESCRIPTION

When detecting an abnormal reset of the CPU caused by the power supply IC in the MG ECU, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





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 5 minutes before touching any of the high-voltage connectors or terminals. After waiting for 5 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 5 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

PROCEDURE

1. CHECK CONNECTOR CONNECTION CONDITION (MG ECU CONNECTOR)
CAUTION: Be sure to wear insulated gloves.
(a) Turn the power switch off.





(b) Remove the service plug grip Removal.
NOTE: 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.
(c) Remove the inverter cover Removal.
NOTICE:
- Wrap the round interlock terminal for the inverter cover with insulating tape to prevent it from shorting to ground.
- Prevent coolant in the inverter reserve tank from entering the inverter.
- Removing the inverter cover causes the MG ECU board to be exposed. Therefore, temporarily install the inverter cover for each area to be inspected.
(d) Check the connections of the MG ECU connectors.
OK:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (IGCT RELAY - MG ECU)
CAUTION: Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.
(b) Remove the IGCT relay from the engine room relay block.
(c) Disconnect connector A42 from the MG ECU.





(d) 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.
3. INSPECT MG ECU (+B VOLTAGE)
CAUTION: Be sure to wear insulated gloves.





(a) Check that the service plug grip is not installed.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





NOTE: Turning the power switch on (IG) with the service plug and inverter cover removed causes interlock switch system DTCs to be stored. Clear the DTCs after performing the inspection.

NG -- CHECK AND REPLACE BATTERY
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY