HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A1B-788

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

DESCRIPTION

If the inverter with converter assembly (MG ECU) is reset due to a problem with the power source in the inverter, the hybrid vehicle control ECU will set this DTC.

DTC No. INF Code DTC Detection Condition Trouble Area
P0A1B 788 Error in reset signal from the inverter assembly power source IC

  • Wire harness or connector

  • Inverter with converter assembly

  • Engine room No. 2 relay block

  • Hybrid vehicle control ECU

WIRING DIAGRAM

A01GY4RE05

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.

Tech Tips

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 (HV)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

    4. Check if DTCs are output.

      Result
      Result Proceed to
      P0A1B-788 only is output. A
      U0110-159, 160, 656, 657 are also output. B

    B

    GO TO DTC CHART Click here

    A

  2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

    CAUTION:

    Be sure to wear insulated gloves.

    Note

    Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector cannot be pulled out.


    1. Turn the power switch off.

    2. Remove the service plug grip. Click here

      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.

    3. Check the connection of the low voltage connector of the inverter with converter assembly.

      OK
      The connector is connected securely and there are no contact problems.

      Tech Tips

      When connecting the connector, insert it with the locking lever in the raised position. Rotate the lever downward and make sure that the connector is pulled into its socket. When the locking lever is in its fully closed position, a click will be heard as its locking claws engage. After the click is heard, pull up on the connector to confirm that it is properly connected.


    NG

    CONNECT SECURELY

    OK

  3. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - ENGINE ROOM NO. 2 R/B)


    1. Remove the ST CUT/IGCT2 relay from the engine room No. 2 relay block.

    2. Disconnect the low voltage connector from the inverter with converter assembly.

    3. Measure the resistance according to the value(s) in the table below.

      A01H1T8E03
      Standard resistance (Check for open)
      LHD
      Tester Connection Switch Condition Specified Condition
      A79-10 (+B) - Engine room No. 2 relay block ST CUT/IGCT2 relay terminal 3 Power switch off Below 1 Ω
      A79-11 (+B2) - Engine room No. 2 relay block ST CUT/IGCT2 relay terminal 3 Power switch off Below 1 Ω
      A79-30 (GND1) - Body ground Power switch off Below 1 Ω
      A79-31 (GND2) - Body ground Power switch off Below 1 Ω
      RHD
      Tester Connection Switch Condition Specified Condition
      A88-10 (+B) - Engine room No. 2 relay block ST CUT/IGCT2 relay terminal 3 Power switch off Below 1 Ω
      A88-11 (+B2) - Engine room No. 2 relay block ST CUT/IGCT2 relay terminal 3 Power switch off Below 1 Ω
      A88-30 (GND1) - Body ground Power switch off Below 1 Ω
      A88-31 (GND2) - Body ground Power switch off Below 1 Ω
      Standard resistance (Check for short)
      LHD
      Tester Connection Switch Condition Specified Condition
      A79-10 (+B) or A79-11 (+B2) - Body ground and other terminals Power switch off 10 kΩ or higher
      RHD
      Tester Connection Switch Condition Specified Condition
      A88-10 (+B) or A88-11 (+B2) - Body ground and other terminals Power switch off 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE CONTROL ECU Click here