Horn System Ford Taurus X I

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

Note. The smart junction box (SJB) is also known as the generic electronic module (GEM).

The horn system consists of the following components

1. Horn switch
2. Clockspring
3. Horn
4. Smart junction box (SJB)

Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105-R0057 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Flex Probe Kit 105-R025C or equivalent

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Principles of Operation

Note. The smart junction box (SJB) is also known as the generic electronic module (GEM).

The smart junction box (SJB) supplies the switched and control voltage to the horn relay (part of the SJB). When the horn switch (part of the steering wheel) is pressed, ground is supplied to the SJB through the clockspring. The SJB then energizes the horn relay sending voltage to the horn, enabling the horn to sound.

The horn switch is part of the steering wheel and sits behind the air bag. There are two sets of contacts on the horn switch that are separated by springs. One set of contacts is connected to ground and the other set is connected to the horn signal circuit. When the driver air bag module is depressed it pushes on the top set of contacts and collapses the springs. When the springs collapse, it allows the contacts to touch and completes the circuit.

The SJB provides a momentary ground to the horn relay when the anti-theft system is armed, and an on then off ground when the panic button is pressed on the integrated keyhead transmitter (IKT).

Inspection and Verification

1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical or electrical damage.

VISUAL INSPECTION CHART

Symptom Chart

Symptom Chart

Pinpoint Test A: The Horn Is Inoperative

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Horn/Cigar Lighter for schematic and connector information.

Normal Operation

The smart junction box (SJB) supplies the switched and control voltage to the horn relay (part of the SJB). When the horn switch (part of the steering wheel) is pressed, the switch closes and ground is applied from the steering wheel switch harness through the clockspring to the horn relay through circuit CRH02 (BU/WH). The horn relay is then energized, applying voltage to the horn through circuit SRH01 (YE/RD), enabling the horn to sound. Ground for the horn is supplied through circuit GD123 (BK/GY).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Steering wheel switch harness
4. Horn
5. Clockspring
6. Horn switch (part of the steering wheel)
7. SJB

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Scheme 8

1. A1 CHECK THE SJB OUTPUT Key in ON position. Enter the following diagnostic mode on the diagnostic tool: SJB DataLogger Select the SJB PID (HORN). Command the horn on and then off. Does the horn sound when commanded on? YES : Go to A2 . NO : Go to A6 .
2. A2 CHECK CIRCUIT CRH02 (BU/WH) FOR AN OPEN Depower the supplemental restraint system (SRS). Refer to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. Disconnect: SJB C2280b Disconnect: Clockspring C2274 Measure the resistance between the clockspring C2274-8, circuit CRH02 (BU/WH), harness side and the SJB C2280b-41, circuit CRH02 (BU/WH), harness side. Is the resistance less than 5 ohms? YES : Go to A3 . NO : REPAIR the circuit. REPOWER the SRS. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
3. A3 CHECK THE CLOCKSPRING FOR AN OPEN Remove the driver air bag module. Refer to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. Disconnect: Upper Clockspring Connector Measure the resistance between the clockspring C2274 pin 8, component side and the upper clockspring connector pin 1, component side; and between the clockspring C2274 pin 5, component side and the upper clockspring connector pin 4, component side. Is the resistance less than 5 ohms? YES : Go to A4 . NO : INSTALL a new clockspring. INSTALL the driver air bag module. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
4. A4 CHECK CIRCUIT GD111 (BK/BU) FOR AN OPEN Measure the resistance between the clockspring C2274-5, circuit GD111 (BK/BU), harness side and ground. Is the resistance less than 5 ohms? YES : Go to A5 . NO : REPAIR the circuit. REPOWER the SRS. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
5. A5 CHECK THE STEERING WHEEL SWITCH HARNESS FOR DAMAGE OR OPENS Inspect the steering wheel switch harness for damage or opens. Is the steering wheel switch harness OK? YES : INSTALL a new steering wheel. REFER to «STEERING COLUMN»(/ford/taurus-x/i-2007-2009/remont/steering-column/#steering-column) article. CLEAR the DTCs. REPEAT the self-test. NO : REPAIR or INSTALL a new steering wheel switch harness. TEST the system for normal operation.
6. A6 CHECK CIRCUIT GD123 (BK/GY) FOR AN OPEN Key in OFF position. Disconnect: Horn C131 Measure the resistance between the horn C131-1, circuit GD123 (BK/GY), harness side and ground. Is the resistance less than 5 ohms? YES : Go to A7 . NO : REPAIR the circuit. TEST the system for normal operation.
7. A7 CHECK CIRCUIT SRH01 (YE/RD) FOR VOLTAGE Measure the voltage between the horn C131-2, circuit SRH01 (YE/RD), harness side, and the horn C131-1, circuit GD123 (BK/GY), harness side, while pressing the horn switch. Is the voltage greater than 10 volts? YES : INSTALL a new horn. REFER to «Horn»(/ford/taurus-x/i-2007-2009/remont/horns/#horn-system) . TEST the system for normal operation. NO : VERIFY the SJB fuse 24 (20A) is OK. If OK, go to A8 .
8. A8 CHECK CIRCUIT SRH01 (YE/RD) FOR AN OPEN Disconnect: SJB C2280e Measure the resistance between the SJB C2280e-5, circuit SRH01 (YE/RD), harness side, and the horn C131-2, circuit SRH01 (YE/RD), harness side. Is the resistance less than 5 ohms? YES : Go to A9 . NO : REPAIR the circuit. TEST the system for normal operation.
9. A9 CHECK FOR CORRECT SJB OPERATION Disconnect all the SJB connectors. Check for: corrosion damaged pins pushed-out pins Connect all the SJB connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new SJB. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#multifunction-electronic-modules-system) article. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.

Pinpoint Test B: The Horn Is Always On

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Horn/Cigar Lighter for schematic and connector information.

The smart junction box (SJB) supplies the switched and control voltage to the horn relay (part of the SJB). When the horn switch (part of the steering wheel) is pressed, the switch closes and ground is applied from the steering wheel switch harness through the clockspring to the horn relay through circuit CRH02 (BU/WH). The horn relay is then energized, applying voltage to the horn through circuit SRH01 (YE/RD), enabling the horn to sound. Ground for the horn is supplied through circuit GD123 (BK/GY).

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Steering wheel switch harness
3. Clockspring
4. Horn switch (part of the steering wheel)
5. SJB

Scheme 9

Scheme 10

1. B1 CHECK CIRCUIT SRH01 (YE/RD) FOR A SHORT TO VOLTAGE Key in OFF position. Disconnect: SJB C2280e Does the horn continue to sound? YES : REPAIR the circuit. TEST the system for normal operation. NO : Go to B2 .
2. B2 CHECK THE HORN SWITCH INPUT Disconnect: SJB C2280b Connect: SJB C2280e Does the horn continue to sound? YES : Go to B6 . NO : Go to B3 .
3. B3 CHECK CIRCUIT CRH02 (BU/WH) FOR A SHORT TO GROUND Depower the supplemental restraint system (SRS). Refer to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. Disconnect: Clockspring C2274 Measure the resistance between the clockspring C2274-8, circuit CRH02 (BU/WH), harness side and ground. Is the resistance greater than 10,000 ohms? YES : Go to B4 . NO : REPAIR the circuit. REPOWER the SRS. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
4. B4 CHECK THE CLOCKSPRING FOR A SHORT TO GROUND Remove the driver air bag module. Refer to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. Connect: Clockspring C2274 Measure the resistance between the SJB C2280b-41, circuit CRH02 (BU/WH), harness side and ground. Is the resistance greater than 10,000 ohms? YES : Go to B5 . NO : INSTALL a new clockspring. INSTALL the driver air bag module. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
5. B5 CHECK THE STEERING WHEEL SWITCH HARNESS FOR DAMAGE OR SHORTS Inspect the steering wheel switch harness for damage or shorts. Is the steering wheel switch harness OK? YES : INSTALL a new steering wheel. REFER to «STEERING COLUMN»(/ford/taurus-x/i-2007-2009/remont/steering-column/#steering-column) article. TEST the system for normal operation. NO : INSTALL a new steering wheel switch harness. INSTALL the driver air bag module. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(/ford/taurus-x/i-2007-2009/remont/airbag/#supplemental-inflatable-restraint-system) article. TEST the system for normal operation.
6. B6 CHECK FOR CORRECT SJB OPERATION Disconnect all the SJB connectors. Check for: corrosion damaged pins pushed-out pins Connect all the SJB connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new SJB. REFER to «MULTIFUNCTION ELECTRONIC MODULES»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#multifunction-electronic-modules-system) article. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.

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REMOVAL AND INSTALLATION

1. Remove the radiator grille. For additional information, refer to «EXTERIOR TRIM AND ORNAMENTATION»(/ford/taurus-x/i-2007-2009/remont/exteriorinterior-trim/#exterior-trim-and-ornamentation) article.
2. Remove the bolt and the horn. Disconnect the electrical connector. To install, tighten to 7 Nm (62 lb-in).
3. To install, reverse the removal procedure.

See also:
• SUPPLEMENTAL RESTRAINT SYSTEM
• STEERING COLUMN
• MULTIFUNCTION ELECTRONIC MODULES
• EXTERIOR TRIM AND ORNAMENTATION
• Pinpoint Test A
• Pinpoint Test B
• Horn