Inspection Procedure

HINT

• If CAN communication malfunctions, the TCM cannot receive the current data from the ECM In this case, the freeze frame data output from the TCM is not updated, so the data will not be useful for the inspection. However, reading the Data List as the first step in troubleshooting is an effective way to find malfunctions.
• The malfunctioning area can be checked using the CAN Bus Check function on the Techstream (See DIAGNOSIS SYSTEM ).

1. CHECK DTC OUTPUT (IN ADDITION TO DTC U0100) 
   1. Connect the Techstream to the DLC3.
   2. Turn the engine switch on (IG)
   3. Turn the Techstream on
   4. Enter the following menus: Powertrain / ECT / Trouble Codes
   5. Read the DTCs using the Techstream.

      Result 

      RESULT REFERENCE
      
      

      Display (DTC Output)	Proceed to
      Only U0100 is output	A
      U0100 and other DTCs are output	B

      HINT.

      If any other codes besides U0100 are output, perform troubleshooting for those DTCs first.

   B: GO TO DTC CHART  (See DIAGNOSTIC TROUBLE CODE CHART  )

   A: Go to Next Step 

2. INSPECT TCM (POWER SOURCE, BODY GROUND) 
   1. Disconnect the TCM connector.
   2. Turn the engine switch on (IG)
   3. Measure the voltage according to the value(s) in the table below

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATION
      
      

      Tester Connection	Switch Condition	Specified Condition
      A58-5 (+B) - A58-2 (E1)	Engine switch on (IG)	11 to 14 V

   4. Turn the engine switch off.
   5. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      E58-2 (E1) - Body ground	Always	Below 1 Ω

      Fig 1: Identifying A58 TCM Connector Terminal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: CHECK TCM POWER SOURCE CIRCUIT  (See TCM POWER SOURCE CIRCUIT  )

   OK: Go to Next Step 

3. CHECK HARNESS AND CONNECTOR (ECM - TCM) 
   1. Disconnect the ECM connector.
   2. Disconnect the TCM connector
   3. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      A6-10 (CAN+) - A58-21 (CAN+)	Always	Below 1 Ω
      A6-9 (CAN-) - A58-13 (CAN-)	Always	Below 1 Ω
      A6-10 (CAN+) or A58-21 (CAN+) - Body ground	Always	10 kΩ or higher
      A6-9 (CAN-) or A58-13 (CAN-) - Body ground	Always	10 kΩ or higher

   Fig 2: Identifying A6 ECM And A58 TCM Connector Terminal
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to Next Step 

4. CHECK IF DTC RECURS 
   1. Clear the DTCs (See DTC CHECK / CLEAR  )
   2. Replace the TCM (See REMOVAL  )

      HINT.

      Replace the TCM with a TCM of a normally functioning vehicle of the same model

   3. Start the engine
   4. Read the DTCs.

      Result 

      RESULT REFERENCE
      
      

      Display (DTC Output)	Proceed to
      No DTC	A
      U0100 is output	B

   B: REPLACE ECM  (See REMOVAL )

   A: Go to Next Step 

5. REPLACE TCM 
   1. Replace the TCM (See REMOVAL  ).

   NEXT: PERFORM A/T CODE REGISTRATION  (See REGISTRATION  )