DTC P1760-87: Lost Communication with Sub Battery Module Missing Message [12/2017 - 10/2023]: Procedure

1. Check the connector connections and contact pressure of the relevant terminals for the shift control ECU connectors.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [12/2017 - ]

   OK

   The connectors are connected securely and there are no contact pressure problems.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  2

1. Disconnect the G81 shift control ECU connector.
2. Disconnect the P6 sub-battery module assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   G81-22 (BUBI) - P6-1 (RO)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   G81-22 (BUBI) or P6-1 (RO) - Body ground and other terminals	Always	10 kΩ or higher

4. Reconnect the P6 sub-battery module assembly connector.
5. Reconnect the G81 shift control ECU connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Connect an oscilloscope between the shift control ECU terminals specified in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Shift Control ECU)
   *b	Waveform (Sub-battery condition signal)

2. Turn the engine switch on (IG) and measure the waveform.

   Tester Connection	Condition	Equipment Setting
   G81-22 (BUBI) - G81-1 (E1)	Engine switch on (IG)	10 V/DIV., 10 ms./DIV.

   HINT: 

   The duty ratio changes according to the vehicle condition.

3. Turn the engine switch off.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SHIFT CONTROL ECU. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023] 

Result: 

NG 

See step  4

1. Disconnect the G81 shift control ECU connector.
2. Connect an oscilloscope between the shift control ECU terminals.
3. Turn the engine switch on (IG) and measure the waveform.

   Tester Connection	Condition	Equipment Setting
   G81-22 (BUBI) - G81-1 (E1)	Engine switch on (IG)	10 V/DIV., 10 ms./DIV.

   Result

   Result	Proceed to
   The waveform does not appear	A
   The waveform appears	B

   NOTE:

   Turning the engine switch on (IG) with the connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

4. Turn the engine switch off.
5. Reconnect the G81 shift control ECU connector.

Result: 

A 

INSPECT SUB-BATTERY MODULE ASSEMBLY. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2017 - 10/2023] 

Result: 

B 

REPLACE SHIFT CONTROL ECU. Refer to  REMOVAL [12/2017 - 09/2018]  , or refer to  REMOVAL [09/2018 - 10/2020]  , or refer to  REMOVAL [10/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]