Pinpoint Test H: The Transmission Control Module (TCM) Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2005 Lincoln Navigator and 2005 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

H1 CHECK THE TCM C1473 FOR DAMAGE
- Key in OFF position.
- Disconnect: TCM C1473.
- Inspect the TCM C1473 for damage.
- Is the TCM C1473 OK?
- Yes : GO to H2.
- No : REPAIR the TCM C1473. CARRY OUT the data link diagnostics test.
H2 CHECK CIRCUITS 1814 (WH/LB) AND 1815 (PK/LB) BETWEEN THE DATA LINK CONNECTOR (DLC) C251 AND THE TCM C1473 FOR AN OPEN
- Measure the resistance between the TCM C1473 pin 6, circuit 1814 (WH/LB), harness side and the DLC C251 pin 6, circuit 1814 (WH/LB), harness side.
  
  Fig 1: Measuring Resistance Between TCM C1473 Pin 6, Circuit 1814 (WH/LB) And DLC C251 Pin 6, Circuit 1814 (WH/LB)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the TCM C1473 pin 2, circuit 1815 (PK/LB), harness side and the DLC C251 pin 14, circuit 1815 (PK/LB), harness side.
  
  Fig 2: Measuring Resistance Between TCM C1473 Pin 2, Circuit 1815 (PK/LB), Harness Side And DLC C251 Pin 14, Circuit 1815 (PK/LB)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : GO to H3.
- No : REPAIR the circuit in question. CARRY OUT the data link diagnostics test.
H3 CHECK FOR CORRECT TCM OPERATION
- Disconnect all the TCM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the TCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new TCM. REFER to AUTOMATIC TRANSMISSION - 6HP26 A. CLEAR the diagnostic trouble codes (DTCs). REPEAT the self-test. CARRY OUT the data link diagnostics test.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.