AA - No Communication With Lighting Control Module

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.

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 pin 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.

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.

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 and circuit 54 (LG/Y).

Is voltage B+?

YES GO to AA9.
NO GO to AA6.

AA6 -

- Remove fuse 8 (15A) from fuse junction panel.
- USing an ohmmeter connected to ground, measure resistance at lighting control module connector 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 the 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 connected to ground, 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 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 and Grand Marquis.

Is resistance less than 5 ohms?

YES GO to
NO SERVICE Town Car circuit 676 (PK/O) or Crown Victoria and Grand marquis circuit 57 (BK) for open. RESTORE vehicle. RETEST system.