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Test E: Horn Chirp Is Inoperative In Program Mode

NOTE: This test applies to vehicles manufactured in Mexico with anti-theft system only. Vehicles manufactured in Mexico are identified by 3FA as first 3 characters of VIN.
  1. Enter and exit program mode. See REMOTE KEYLESS ENTRY TRANSMITTER PROGRAMMING  under PROGRAMMING. If horn chirp is not heard when program mode was entered and exited, go to next step. If horn chirp is heard when program mode was entered and exited, system is operating properly at this time.
  2. Using NGS tester, monitor RAP PID CHIRP. If RAP PID CHIRP indicates ENABLED, go to next step. If RAP PID CHIRP does not indicate ENABLED, ENABLE RAP ACTIVE COMMAND HORN CHIRP CONFIGURATION, then go to step  1 . If horn chirp is still not heard, go to next step.
  3. Turn ignition switch to LOCK position. Remove horn relay from relay box. Relay box is located behind left side of instrument panel. Disconnect Remote Anti-Theft Personality (RAP) module 22-pin harness connector C404. RAP module is located in luggage compartment, behind right trim panel. Measure resistance of Green/Orange wire between RAP module 22-pin harness connector C404 terminal No. 20 and horn relay 5-pin harness connector terminal No. 85. See Figure and Fig 1 . Resistance should be less than 5 ohms. Check resistance between ground and horn relay 5-pin harness connector terminal No. 85 (Green/Orange wire). Resistance should be more than 10 k/ohms. If resistances are not as specified, repair open or short to ground in Green/Orange wire. Retest system operation. If resistances are as specified, reinstall horn relay and operate horn manually. If horn operates manually, replace RAP module. See REMOTE ANTI-THEFT PERSONALITY MODULE  under REMOVAL & INSTALLATION. Retest system operation. If horn does not operate manually, repair horn circuits as necessary. See HORN article.
Fig 1: Identifying Horn Relay 5-Pin Harness Connector Terminals
G97J28125Courtesy of FORD MOTOR CO.