Pinpoint Test F: The Powertrain Control Module (PCM) Does Not Respond To The Diagnostic Tool: Testing

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

F1 CHECK THE PCM C175B FOR DAMAGE
- Key in OFF position.
- Disconnect: PCM C175b.
- Is the PCM C175b OK?
- Yes : GO to F2.
- No : REPAIR PCM C175b. CARRY OUT the PINPOINT TEST PC: DATA LINK DIAGNOSTICS TEST .
F2 CHECK HIGH SPEED CONTROLLER AREA NETWORK (CAN) CIRCUITS 1908 (WH) AND 1909 (BK) BETWEEN THE DATA LINK CONNECTOR (DLC) C251 AND THE PCM C175B FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the PCM C175b-11, circuit 1908 (WH), harness side and the DLC C251-6, circuit 1908 (WH), harness side; and between the PCM C175b-23, circuit 1909 (BK), harness side and the DLC C251-14, circuit 1909 (BK), harness side.
  
  Fig 1: Measuring High Speed Controller Area Network (CAN) Circuits 1908 (WH) And 1909 (BK) Between Data Link Connector (DLC) C251 And PCM C175B
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : GO to F3.
- No : REPAIR the circuit in question. CLEAR the diagnostic trouble codes (DTCs). REPEAT the self-test. CARRY OUT the PINPOINT TEST PC: DATA LINK DIAGNOSTICS TEST .
F3 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the PCM module 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 PCM. REFER to ELECTRONIC ENGINE CONTROLS . CLEAR the DTCs. REPEAT the self-test. CARRY OUT the PINPOINT TEST PC: 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 PINPOINT TEST PC: DATA LINK DIAGNOSTICS TEST .