DTC P0A1B-94: Drive Motor "A" Control Module Unexpected Operation [08/2020 - ]: Procedure

1. Check the connection of the negative (-) and positive (+) auxiliary battery terminals.

   OK

   The terminals are connected securely and there is no contact problem.

   HINT: 

   If performing a reproduction test, turn the power switch on (IG) and shake the wire harnesses vertically and horizontally before checking for DTCs.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  2

1. Check the installation condition of the ground wires OB.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   The ground wires OB are securely installed.

   HINT: 

   If performing a reproduction test, turn the power switch on (IG) and shake the wire harnesses vertically and horizontally before checking for DTCs.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  7

Result: 

OK 

See step  3

1. Disconnect the cable from the negative (-) auxiliary battery terminal.
2. Disconnect the cable from the positive (+) auxiliary battery terminal.
3. Check the fusible link block assembly (IGCT) for improper installation.

   OK

   The fusible link block assembly is installed securely and there is no contact problem.

4. Disconnect the 7A fusible link block assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   7A-1 - A-1 (Positive (+) auxiliary battery terminal)	Power switch off	Below 1 Ω

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Fusible Link Block Assembly
   *a	Component without harness connected (Fusible Link Block Assembly)

6. Reconnect the 7A fusible link block assembly connector.
7. Reconnect the cable from the positive (+) auxiliary battery terminal.
8. Reconnect the cable from the negative (-) auxiliary battery terminal.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  8

Result: 

OK 

See step  4

1. Check the IGCT relay for improper installation.

   OK

   The relay is installed securely.

   HINT: 

   If performing a reproduction test, turn the power switch on (IG) and gently vibrate the IGCT relay with a finger before checking for DTCs.

2. Remove the IGCT relay from the No. 3 relay block.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	No. 3 Relay Block
   *2	IGCT Relay

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	IGCT Relay

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Auxiliary battery voltage not applied between terminals 1 and 2	10 kΩ or higher
   	Auxiliary battery voltage applied between terminals 1 and 2	Below 1 Ω

4. Install the IGCT relay.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  9

Result: 

OK 

See step  5

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
4. Check for DTCs.

   HINT: 

   Check the DTCs that were output when the vehicle was brought to the workshop.

   Powertrain > Hybrid Control > Trouble Codes 

   Result

   Result	Proceed to
   P0A1B-94 only is output	A
   DTCs except P0A1B-94 are output	B

5. Turn the power switch off.

Result: 

A 

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS. Refer to  DTC CHECK / CLEAR [08/2020 - ] 

Result: 

B 

GO TO DTC CHART (HYBRID CONTROL SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2020 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - ] 

Result

Result: 

NEXT 

See step  10

Result

Result: 

NEXT 

See step  10

Result

Result: 

NEXT 

See step  10

Result

Result: 

NEXT 

See step  10

See step  3

Result

Result: 

NEXT 

See step  11

1. Turn the power switch on (IG) and wait for 2 minutes or more.
2. Turn the power switch off.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  12

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

   Powertrain > Hybrid Control > Trouble Codes 

4. Check for DTCs.

   Result

   Result	Proceed to
   No DTCs are output	A
   P0A1B-94 only is output	B
   DTCs except P0A1B-94 are output	C

5. Turn the power switch off.

Result: 

A 

END 

Result: 

B 

REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS. Refer to  DTC CHECK / CLEAR [08/2020 - ] 

Result: 

C 

GO TO DTC CHART (HYBRID CONTROL SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2020 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - ]