2003 FORD MUSTANG horn

DESCRIPTION AND OPERATION
Horn
The horn system consists of the following:
zdual horns (one high-pitched, one low- pitched)
z horn switch (located underneath the driver side air bag module [043B13]).
z horn relay (located in the central junction box [CJB]).
SECTION 413-
06: Horn 2003 Mustang Workshop Manual Klj . 1 ba
12003 Mustang Workshop Manual
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DIAGNOSIS AND TESTING
Horn
Refer to Wiring Diagrams Cell
44 , Horns/Cigar Lighter for schematic and connector information.
Inspection and Verification 1. Verify the customer concern by operating the horn (13832).
2. Visually inspect for obvious signs of mechanical and electrical damage.
3. If fault is not visually evident, determine the symptom and proceed to Symptom Chart.
Symptom Chart SECTION 413-
06: Horn 2003 Mustang Workshop Manual Special Tool(s)
73 Digital Multimeter or
equivalent
105-
R0051
Visual Inspection Chart Mechanical Electrical
z
Damaged horns
z Damaged horn switch
z Damaged air bag sliding contact
(14A664) z
Blown battery junction box (BJB) Fuse Horn
Relay (20A)
z Damaged wiring harness
z Damaged connections
z Damaged horn relay
z Damaged horn switch
Symptom Chart Condition
Possible Sources Action
z The horn does not
sound z
BJB Fuse Horn Relay (20A).
z Circuitry.
z Horn relay.
z Air bag sliding contact.
z Horn switch.
z Horns. z
GO to
Pinpoint Test A .
z The horn sounds
continuously z
Circuitry.
z Horn relay.
z Remote entry system (generic
electronic module [GEM]) z
GO to
Pinpoint Test B . Klj . 1 ba
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Pinpoint Tests
PINPOINT TEST A: THE HORN DOES NOT SOUND module.
z Horn switch. Test Step Result / Action to
Take A1 CHECK POWER SUPPLY TO HORN RELAY
z
Disconnect: Horn Relay.
z Measure the voltage between the horn relay connector Pin 2,
Circuit 460 (YE/LB), harness side and ground; and between the
horn relay connector Pin 5, Circuit 460 (YE/LB), harness side and
ground.
z Are the voltages greater than 10 volts? Yes
GO to
A2 .
No
REPAIR the circuit in
question. TEST the
system for normal
operation. A2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring Diagrams Cell 149.
z Is the horn relay OK? Yes
GO to
A3 .
No
INSTALL a new horn
relay. TEST the
system for normal
operation. A3 CHECK HORN SWITCH SIGNAL TO HORN RELAY
z
Measure the resistance between horn relay connector Pin 1,
Circuit 6 (YE/LG), harness side and ground under the following
conditions:
Horn Switch Position Horn Switch Position Resistance
Pressed Less than 5 ohms
Released Greater than 10,000 ohms Yes
GO to
A4 .
No
GO to A5 . Klj . 2 ba
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z
Are the resistances correct? A4 CHECK WIRE BETWEEN HORN RELAY AND HORN
z
Key in OFF position.
z Disconnect: Horn C1262.
z Disconnect: Horn C1261.
z Measure the resistance between the horn relay connector Pin 3,
Circuit 1 (DB), harness side and horn C1261 or horn C1256
harness side; and between the horn relay connector Pin 3, Circuit
1 (DB), harness side and ground.
z Is the resistance less than 5 ohms between the horn relay and
the horns, and greater than 10,000 ohms between the horn
relay and ground? Yes
INSTALL new horns.
TEST the system for
normal operation.
No
REPAIR the circuit.
TEST the system for
normal operation.
A5 CHECK WIRE BETWEEN HORN RELAY AND AIR BAG SLIDING
CONTACT z
Key in OFF position.
z Deactivate the air bag system; refer to Section 501 - 20B .
z Disconnect: Air Bag Sliding Contact C218a.
z Measure the resistance between air bag sliding contact C218a Pin
2, Circuit 6 (YE/LG), harness side and horn relay connector Pin 1,
Circuit 6 (YE/LG) harness side.
z Is the resistance less than 5 ohms? Yes
GO to
A6 .
No
REPAIR the circuit.
TEST the system for
normal operation. A6 CHECK AIR BAG SLIDING CONTACT
z
Disconnect the steering wheel switch harness from the air bag
sliding contact.
z Measure the resistance between upper air bag sliding contact Yes
GO to
A7 . Klj . 3 ba
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PINPOINT TEST B: THE HORN SOUNDS CONTINUOUSLY connector Pin 3, Circuit 6 (component side), and air bag sliding
contact C218a Pin 2, Circuit 6 (component side).
z Is the resistance less than 5 ohms? No
INSTALL a new air
bag sliding contact.
REFER to
Section 501 - 20B . TEST the
system for normal
operation. A7 CHECK THE STEERING WHEEL SWITCH HARNESS
z
Inspect the steering wheel switch harness for chafing, opens or
possible short to ground.
z Is the steering wheel switch harness OK? Yes
INSTALL a new horn
switch. REFER to
Switch
— Horn . TEST
the system for normal
operation.
No
INSTALL a new
steering wheel switch
harness. TEST the
system for normal
operation. Test Step Result / Action to Take
B1 CHECK HORN CIRCUIT 1 (DB)
z
Key in OFF position.
z Disconnect: Horn Relay.
z Does the horn continue to sound? Yes
REPAIR Circuit 1 (DB) for short to battery. TEST
the system for normal operation.
No
GO to
B2 .
B2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring
Diagrams Cell 149.
z Is the horn relay OK? Yes
REINSTALL the horn relay. GO to
B3 .
No
INSTALL a new horn relay. TEST the system for
normal operation. B3 CHECK CIRCUIT 6 (YE/LG)
z
Disconnect: Air Bag Sliding Contact
C218a .
z Does the horn continue to sound? Yes
GO to
B4 .
No
RECONNECT the air bag sliding contact. GO to
B5 .
B4 CHECK GEM INPUT
z
Disconnect: GEM C201e. Yes Klj . 4 ba
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z
Does the horn continue to sound? REPAIR Circuit 6 (YE/LG). TEST the system for
normal operation.
No
INSTALL a new GEM; REFER to
Section 419 - 10 .
TEST the system for normal operation. B5 CHECK THE AIR BAG SLIDING
CONTACT z
Deactivate the air bag system. Refer
to Section 501 - 20B .
z Disconnect the steering wheel switch
harness from the air bag sliding
contact.
z Does the horn continue to sound? Yes
INSTALL a new air bag sliding contact. REFER to
Section 501
- 20B . TEST the system for normal
operation.
No
GO to B6 .
B6 CHECK STEERING WHEEL SWITCH
HARNESS z
Inspect the steering wheel switch
harness for shorts, opens, or any
damage.
z Is the steering wheel switch
harness OK? Yes
INSTALL a new horn switch. REFER to
Switch —
Horn . TEST the system for normal operation.
No
INSTALL a new steering wheel switch harness.
TEST the system for normal operation. Klj . 5 ba
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REMOVAL AND INSTALLATION
Switch —
Horn
Removal 1. Remove the driver side air bag module (043B13). Refer to Section 501 - 20B .
2. Remove the switches. 1. Disconnect the horn wire from the switches.
2. Remove the horn switch screws and remove the switches.
Installation 1. To install, reverse the removal procedure. zProve out the air bag system. Refer to Section 501 - 20B .
SECTION 413-
06: Horn 2003 Mustang Workshop Manual Klj . 1 ba
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Inspection and Verification
1. Verify the customer concern by operating the system.
2. Visually inspect for obvious signs of mechanical or electrical damage.
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the diagnostic tool does not communicate with the vehicle, refer to the diagnostic tool manual.
5. Carry out the DATA LINK DIAGNOSTIC TEST. If the diagnostic tool responds with: zCKT 914, CKT 915 or CKT70 - ALL ECUS NO RESP/NOT EQUIP, refer to Section 418 -
00 .
z NO RESP/NOT EQUIP for the generic electronic module (GEM), go to Pinpoint Test A.
z NO RESP/NOT EQUIP for the instrument cluster module (ICM), refer to Section 413 - 01 .
z System passed, retrieve and record the continuous diagnostic trouble codes (DTCs),
erase the continuous DTCs and carry out self- test diagnostics for the GEM or ICM.
6. If the GEM or ICM DTCs retrieved are related to the concern, go to the GEM or ICM Diagnostic Trouble Code (DTC) Index.
7. If no DTCs related to the concern are retrieved, proceed to the Symptom Chart to continue diagnostics.
GEM DIAGNOSTIC TROUBLE CODE (DTC) INDEX Visual Inspection Chart Mechanical Electrical
z
Power window
regulator
z Window run
weatherstrip
z Door window glass z
Central junction box (CJB) circuit breaker 43 (20A), fuse 39
(5A) or 23 (15A)
z Battery junction box (BJB) fuse HTD BL (40A)
z Generic electronic module (GEM)
z Window regulator control switch
z Window regulator motor
z Instrument cluster module (ICM)
z Heated rear window relay
z Rear window defrost switch
z Heated rear window grid
z Circuitry DTC Description Source Action
B1217 Horn Relay Output Driver
Circuit Failure GEM GO to
Section 501 - 14B .
B1218 Horn Relay Output Driver
Short to Battery GEM GO to
Section 501 - 14B .
B1312 Lamp Headlamp Input Circuit GEM GO to
Section 413 - 09 . Klj . 2 ba
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