Pinpoint Test H: The Lighting Control Module (LCM) Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. 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.

H1 CHECK THE LCM C2145A FOR DAMAGE
- Key in OFF position.
- Disconnect: LCM C2145a.
- Inspect the LCM C2145a for damage.
- Is the LCM C2145a OK?
Yes : GO to H2.

No : REPAIR the LCM C2145a as necessary. CARRY OUT the diagnostic tool data link test.
H2 CHECK THE SCP CIRCUITS BETWEEN THE DLC AND THE LCM FOR AN OPEN
- Measure the resistance between the LCM C2145a-8, circuit 914 (TN/OG), harness side and the DLC C251-2, circuit 914 (TN/OG), harness side.
  
  Fig 1: Checking The SCP Circuits Between The DLC And The LCM For An Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the LCM C2145a-16, circuit 915 (PK/LB), harness side and the DLC C251-10, circuit 915 (PK/LB) harness side.
  
  Fig 2: Checking The SCP Circuits Between The DLC And The LCM For An Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to H3.

No : REPAIR the circuit. CARRY OUT the diagnostic tool data link test.
H3 CHECK FOR CORRECT LCM OPERATION
- Disconnect all the LCM connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the LCM 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 LCM. REFER to MULTIFUNCTION ELECTRONIC MODULES . 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 diagnostic trouble codes (DTCs). REPEAT the self-test.