Self-Diagnostic System

NOTE: Before beginning self-diagnostics, perform TROUBLE SHOOTING .

Connect New Generation Star (NGS) tester to Data Link Connector (DLC) located below instrument panel and select vehicle to be tested from NGS tester menu. If NGS tester does not communicate with vehicle, ensure program card is properly installed, check connections to vehicle and/or check ignition switch position. If NGS tester still does not communicate with vehicle, refer to NGS tester manual.

Using NGS tester, perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM in MODULE COMMUNICATIONS NETWORK -- EXCURSION & F250-F550 SUPER DUTY PICKUPS article. If NGS tester displays CKT 914, CKT 915 or CKT 70=ALL ECUS NO RESP/NOT EQUIP, see MODULE COMMUNICATIONS NETWORK -- EXCURSION & F250-F550 SUPER DUTY PICKUPS article to diagnosis network concern. If NGS tester displays NO RESP/NOT EQUIP for Generic Electronic Module (GEM), perform TEST A: NO COMMUNICATION WITH GENERIC ELECTRONIC MODULE under SYSTEM TESTS.

If NGS tester displays SYSTEM PASSED, retrieve and record continuous DTCs. Erase continuous DTCs. Perform self-test diagnostics for GEM using NGS tester. If GEM DTCs are retrieved, see GENERIC ELECTRONIC MODULE DTC DEFINITIONS table to continue diagnosis. If no DTCs were retrieved, repair system by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

GENERIC ELECTRONIC MODULE DTC DEFINITIONS

DTC ⁽¹⁾

Description

Perform Test

B1340

Chime Input Request Circuit Short To Ground

B1342

GEM Is Defective

⁽²⁾

B1355

Ignition RUN Circuit Failure

B1359

Ignition RUN/ACC Circuit Failure

B1462

Seat Belt Switch Circuit Failure

B1577

Lamp Park Input Circuit Short To Battery

⁽¹⁾	Codes listed in this table are only for testing covered in this article. For complete DTC listing, see MODULE COMMUNICATIONS NETWORK -- EXCURSION & F250-F550 SUPER DUTY PICKUPS article.

⁽²⁾	Clear DTCs. Retrieve DTCs. If DTC B1342 is retrieved, replace GEM and retest system operation.