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

1. Connect the Techstream 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 → See step   4 

A: Go to next step 

1. Turn the power switch off.
2. Remove the service plug grip. Refer to PRECAUTION .
   NOTE:

   • After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair information because this may cause a malfunction.
   • Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector does not pull out.
   Fig 1: Identifying Inverter With Converter Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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.

   HINT: 

   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: Go to next step 

1. Remove the IGCT2 relay from the engine room No. 2 relay block.
2. Disconnect the low voltage connector from the inverter with converter assembly.
   Fig 2: Checking Harness And Connector (Hybrid Vehicle Control ECU-Inverter With Converter Assembly)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the resistance according to the value(s) in the table below.
   Fig 3: Checking Harness And Connector (Inverter With Converter Assembly -- Engine Room No. 2 R/B)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance (Check for open)

   Tester Connection	Switch Condition	Specified Condition
   A77-10 (+B) - Engine room No. 2 relay block IGCT2 relay terminal 3	Power switch off	Below 1 Ω
   A77-11 (+B2) - Engine room No. 2 relay block IGCT2 relay terminal 3	Power switch off	Below 1 Ω
   A77-30 (GND1) - Body ground	Power switch off	Below 1 Ω
   A77-31 (GND2) - Body ground	Power switch off	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Switch Condition	Specified Condition
   A77-10 (+B) or A77-11 (+B2) - Body ground and other terminals	Power switch off	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   5