DTC P1752-31: Fail Safe Signal (Gear Shift Control Module "B" to "A") No Signal [11/2021 - ]: Procedure

Pre-procedure1

1. Connect an oscilloscope between the transmission floor shift assembly (shift control ECU) terminals specified in the table below.
2. Turn the ignition switch to ON.

   Procedure1

3. Measure the waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Transmission Floor Shift Assembly (Shift Control ECU))
   *b	Waveform (Fail Safe Signal)

   Tester Connection	Condition	Equipment Setting
   D39-14 (FS) - D39-9 (E1)	Ignition switch ON	10 V/DIV., 20 ms./DIV.

   HINT: 

   Perform the inspection with the connector of the shift control ECU and shift actuator ECU connected.

   Result

   Proceed to
   OK
   NG

   Post-procedure1

4. Turn the ignition switch off.

Result: 

OK 

REPLACE TRANSMISSION FLOOR SHIFT ASSEMBLY (SHIFT CONTROL ECU). Refer to  REMOVAL [11/2021 - ] 

Result: 

NG 

See step  2

Pre-procedure1

1. Disconnect the D39 transmission floor shift assembly (shift control ECU) connector.
2. Disconnect the B78 shift control actuator assembly (shift actuator ECU) connector.

   Procedure1

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D39-14 (FS) - B78-6 (FS)	Always	Below 1 Ω
   D39-14 (FS) or B78-6 (FS) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

   Post-procedure1

4. Connect the shift control actuator assembly (shift actuator ECU) connector.
5. Connect the transmission floor shift assembly (shift control ECU) connector.

Result: 

OK 

REPLACE SHIFT CONTROL ACTUATOR ASSEMBLY (SHIFT ACTUATOR ECU). Refer to  REMOVAL [11/2021 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR