DTC U0100-87: Lost Communication with ECM/PCM "A" Missing Message [06/2018 - 09/2022]: Procedure

1. Disconnect the C80 TCM connector.
2. Turn the engine switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   C80-1 (+B) - C80-2 (E1)	Engine switch on (IG)	11 to 14 V

4. Turn the engine switch off.
5. Connect the C80 TCM connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE OF TCM) 

Result: 

OK 

See step  2

1. Disconnect the A47 ECM connector.
2. Disconnect the C80 TCM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C80-18 (CAN+) - A47-7 (CANP)	Always	Below 1 Ω
   C80-17 (CAN-) - A47-17 (CANN)	Always	Below 1 Ω
   C80-18 (CAN+) or A47-7 (CANP) - Body ground	Always	10 kΩ or higher
   C80-17 (CAN-) or A47-17 (CANN) - Body ground	Always	10 kΩ or higher

4. Connect the C80 TCM connector.
5. Connect the A47 ECM connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - TCM) 

Result: 

OK 

See step  3

1. Replace the TCM.

   Refer to COMPONENTS [06/2018 - 01/2019] , or refer to COMPONENTS [01/2019 - 03/2019] , or refer to COMPONENTS [03/2019 - 09/2024]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Perform Registration and Initialization.

   for Registration: Refer to REGISTRATION [06/2018 - 09/2024]

   for Initialization: Refer to INITIALIZATION [06/2018 - 09/2022]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs.

   Powertrain > Transmission > Clear DTCs 

5. Turn the engine switch off and wait for at least 30 seconds.
6. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
7. Enter the following menus: Powertrain / Transmission / Trouble Codes.
8. Read the DTCs.

   Powertrain > Transmission > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTC U0100-87 is output	B

Result: 

A 

END 

Result: 

B 

See step  6

1. Replace the ECM.

   Refer to COMPONENTS [06/2018 - 09/2022]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

PERFORM INITIALIZATION. Refer to  INITIALIZATION [06/2018 - 09/2022]