FixVault

Self-Diagnostic System

WARNING: This page is about a different car, the 2002 Mercury Grand Marquis and 2002 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Rear window defogger is controlled by Lighting Control Module (LCM) which utilizes a self-diagnostic system which may store a Diagnostic Trouble Code (DTC) if a problem exists in system. Before performing any testing, see TROUBLE SHOOTING .

If all components are okay, connect Worldwide Diagnostic System (WDS) tester or New Generation Star (NGS) tester to Data Link Connector (DLC), located below left side of instrument panel. See Figure. Using WDS or NGS tester, perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM in MODULE COMMUNICATIONS NETWORK - CROWN VICTORIA & GRAND MARQUIS article. If WDS or NGS tester displays NO RESP/NOT EQUIP, perform TEST A: NO COMMUNICATION WITH LIGHTING CONTROL MODULE  under SYSTEM TESTS. If WDS or NGS tester displays SYSTEM PASSED, retrieve and record continuous DTCs. Erase continuous DTCs and perform LCM self-test. Perform appropriate test in accordance with DTC retrieved. See LIGHTING CONTROL MODULE DIAGNOSTIC TROUBLE CODE INDEX  table. DTCs listed in this table are only for testing covered in this article. For complete DTC listing, see MODULE COMMUNICATIONS NETWORK - CROWN VICTORIA & GRAND MARQUIS article. If no DTCs are retrieved, repair by symptom. See SYMPTOM INDEX  table under SYSTEM TESTS.

LIGHTING CONTROL MODULE DIAGNOSTIC TROUBLE CODE INDEX

DTC (1) Description Perform Test
B1342 ECU Defective (2)
B1345 Rear Window Defogger Input Short To Ground B 
B1555 Ignition RUN/START Circuit Failure (3)
(1) DTCs listed in this table are only for testing covered in this article. For complete DTC listing, see MODULE COMMUNICATIONS NETWORK - CROWN VICTORIA & GRAND MARQUIS article.
(2) Using WDS or NGS tester, retrieve and record all DTCs. Clear DTCs and perform self-test. If DTC B1342 is retrieved again, replace LCM. See LIGHTING CONTROL MODULE  under REMOVAL & INSTALLATION.
(3) For ignition switch diagnose, see STEERING COLUMN SWITCHES article.