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

C1 CHECK THE PCM C175T FOR DAMAGE
- Key in OFF position.
- Disconnect: PCM C175t.
- Inspect the PCM C175t for damage
- Is the PCM C175t OK?
- Yes : GO to C2.
- No : REPAIR the PCM C175t as necessary. CARRY OUT the diagnostic tool data link test.
C2 CHECK CIRCUITS 914 (TN/OG) AND 915 (PK/LB) BETWEEN THE DLC C251 AND THE PCM C175T FOR AN OPEN
- Key in OFF position.
- Disconnect: PCM C175t.
- Measure the resistance between the PCM C175t-35, circuit 914 (TN/OG), harness side and the DLC C251-2, circuit 914 (TN/OG), harness side.
  
  Fig 1: Measuring Resistance Between PCM C175t-35, Circuit 914 (TN/OG), Harness Side And The DLC C251-2, Circuit 914 (TN/OG), Harness Side
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the PCM C175t-36, circuit 915 (PK/LB), harness side and the DLC C251-10, circuit 915 (PK/LB), harness side.
  
  Fig 2: Measuring Resistance Between PCM C175t-36, Circuit 915 (PK/LB), Harness Side And The DLC C251-10, Circuit 915 (PK/LB), Harness Side
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to C3.
- No : REPAIR the circuit in question. CARRY OUT the diagnostic tool data link test.
C3 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the PCM 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 . CARRY OUT the diagnostic tool data link 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.