AA - No Communication With Lighting Control Module (LCM)

Pinpoint Test AA: No Communication With Lighting Control Module

AA1 - Check Circuit 195 (T/W) For Power

- Disconnect lighting control module connector C3.
- Using a voltmeter, measure for voltage at lighting control module connector Pin C3-6, Circuit 195 (T/W).

Is voltage B+?

YES GO to AA5.
NO GO to AA2.

AA2 - Check Circuit 195 (T/W) For Short To Ground

- Remove fuse 4 (15A) from fuse junction panel.
- Using an ohmmeter connected to ground, measure resistance at lighting control module connector C3-6, Circuit 195 (T/W).

Is resistance less than 10K ohms?

YES SERVICE circuit 195 (T/W) for short to ground. REPLACE fuse 4 (15A). RESTORE vehicle. RETEST System.
NO GO to AA3.

AA3 - Check Supply To Fuse 4 (15A)

- Remove fuse 4 (15A) from fuse junction panel.
- Using a voltmeter, measure for voltage at fuse 4 input cavity.

Is voltage B+?

YES GO to AA4.
NO SERVICE supply to fuse 4 (15A). RESTORE vehicle. RETEST system.

AA4 - Check Circuit 195 (T/W) For Open

- Using an ohmmeter, measure resistance of circuit 195 (T/W) between lighting control module connector pin C3-6 and output cavity of Fuse 4 (15A).

Is resistance 5 ohms or less?

YES REPLACE fuse 4 (15A). RESTORE vehicle. RETEST system.
NO SERVICE circuit 195 (T/W) for open. RESTORE vehicle. RETEST system.

AA5 - Check Circuit 54 (LG/Y) For Power

- Disconnect lighting control module connector C3.
- Using a voltmeter, measure for voltage at lighting control module connector pin C3-11, circuit 54 (LG/Y).

Is voltage B+?

YES GO to AA9.
NO GO to AA6.

AA6 - Check Circuit 54 (LG/Y) For Short To Ground

- Remove fuse 8 (15A) from fuse junction panel.
- Using an ohmmeter connected to ground, measure resistance at lighting control module pin C3-11, circuit 54 (LG/Y).

Is resistance less than 10K ohms?

YES SERVICE circuit 54 (LG/Y) for short to ground. REPLACE fuse 8 (15A). RESTORE vehicle. RETEST system.
NO GO to AA7.

AA7 - Check Supply To Fuse 8 (15A)

- Remove fuse 8 (15A) from fuse junction panel.
- Using a voltmeter, measure for voltage at fuse 8 input cavity.

Is voltage B+?

YES GO to AA8.
NO SERVICE supply to fuse 8 (15A). RESTORE vehicle. RETEST system.

AA8 - Check Circuit 54 (LG/Y) For Open

- Using an ohmmeter, measure resistance of circuit 54 (LG/Y) between lighting control module connector pin C3-11 and output cavity of fuse 8.

Is resistance 5 ohms or less?

YES REPLACE fuse 8 (15A). RESTORE vehicle. RETEST system.
NO SERVICE circuit 54 (LG/Y) for open. RESTORE vehicle. RETEST system.

AA9 - Check Logic To Ground For Open

- Using an ohmmeter connected to ground, measure resistance at lighting control module connector pin C3-9, circuit 676 (PK/O) Town Car or circuit 57 (BK) Crown Victoria, Grand Marquis.

Is resistance less than 5 ohms?

YES GO to communication network diagnostics to diagnose network concern.
NO SERVICE Town Car circuit 676 (PK/O) or Crown Victoria, Grand Marquis circuit 57 (BK) for open. RESTORE vehicle. RETEST system.