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

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

B1 CHECK THE TCM CONNECTOR FOR DAMAGE
- Key in OFF position.
- Disconnect: TCM C2352b (FNR5) or C1533 (6-speed).
- Inspect the TCM connector for damage.
- Is the TCM connector OK?
Yes : For TCM C2352b (FNR5) GO to B2.

For TCM C1533 (6-speed) GO to B3.

No : REPAIR the TCM C2352b (FNR5) or C1533 (6-speed) as necessary. CONNECT the TCM C2352b (FNR5) or C1533 (6-speed). CARRY OUT the data link diagnostics test.
B2 CHECK THE HIGH SPEED CAN CIRCUITS BETWEEN THE DLC AND THE TCM C2352B FOR AN OPEN
- Measure the resistance between the TCM C2352b-1, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 1: Checking High Speed CAN Circuits Between DLC And TCM C2352B For Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the TCM C2352b-13, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 2: Checking High Speed CAN Circuits Between DLC And TCM C2352B For Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to B4.

No : REPAIR the circuit. CONNECT the TCM C2352b. CARRY OUT the data link diagnostics test.
B3 CHECK THE HIGH SPEED CAN CIRCUITS BETWEEN THE DLC AND THE TCM C1533 FOR AN OPEN
- Measure the resistance between the TCM C1533-14, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 3: Checking High Speed CAN Circuits Between DLC And TCM C1533 For Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the TCM C1533-6, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 4: Checking High Speed CAN Circuits Between DLC And TCM C1533 For Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to B4.

No : REPAIR the circuit. CONNECT the TCM C1533. CARRY OUT the data link diagnostics test.
B4 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 - 6 SPEED or AUTOMATIC TRANSAXLE/TRANSMISSION - FNR5 . 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.