DTC U0103-87: Lost Communication with Gear Shift Control Module "A" Missing Message [03/2017 - 05/2023]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Enter the following menus: Health Check.
4. Check for DTCs.

   Result

   Result	Proceed to
   DTC P176D-12 does not output.	A
   DTC P176D-12 is output.	B

5. Turn the engine switch off.

Result: 

B 

GO TO DTC CHART (P176D-12). Refer to  DTC P176D-12: IG2 Signal (Gear Shift Control Module "A") Circuit Short to Battery [03/2017 - 05/2023] 

Result: 

A 

See step  2

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 [03/2017 - ]

   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  3

1. Disconnect the P74 shift control ECU connector.
2. Disconnect the A58 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Switch Condition	Specified Condition
   P74-6(CA2H) - A58-12(CANU)	Engine switch off	Below 1 Ω
   P74-5(CA2L) - A58-25(CAND)	Engine switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Switch Condition	Specified Condition
   P74-6(CA2H) or A58-12(CANU) - Body ground and other terminals	Engine switch off	10 kΩ or higher
   P74-5(CA2L) or A58-25(CAND) - Body ground and other terminals	Engine switch off	10 kΩ or higher

4. Reconnect the A58 ECM connector.
5. Reconnect the P74 shift control ECU connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Check that the voltage between the terminals of the sub-battery module assembly is 0 V.

   Refer to REMOVAL [03/2017 - 05/2023]

2. Disconnect the cable from the negative (-) battery terminal.
3. Disconnect the shift control ECU connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Shift Control ECU)

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   P74-6(CA2H) - P74-5(CA2L)	20°C (68°F)	108 to 132 kΩ

5. Reconnect the shift control ECU connector.
6. Connect the cable to the negative (-) battery terminal.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE SHIFT CONTROL ECU. Refer to  REMOVAL [03/2017 - 05/2023] 

Result: 

NG 

REPLACE ECM. Refer to  REMOVAL [03/2017 - 05/2023]