413-06-1 Horn 413-06-1
SECTION 413-06 Horn
VEHICLE APPLICATION:2008.50 Mondeo
CONTENTS PAGE
DIAGNOSIS AND TESTING
Horn.................................................................................................................................... 413-06-2
Principles of Operation....................................................................................................... 413-06-2
Inspection and Verification.................................................................................................. 413-06-2
Diagnostic Trouble Code (DTC) Index Chart...................................................................... 413-06-2
Symptom Chart................................................................................................................... 413-06-2
Pinpoint Tests..................................................................................................................... 413-06-3
413-06-2 Horn 413-06-2
DIAGNOSIS AND TESTING
Horn
Principles of Operation Visual Inspection Chart
The horn system consists of a relay, a steering Electrical
wheel switch and either one or two horns. The • Fuse(s)
horn(s) receives voltage from the switched side of • Wiring harness
the relay, and the relay switch is controlled on its
ground side by the steering wheel switch. • Electrical connector(s)
• Horn switch
The horn relay, is located in the Battery junction
box (BJB) and is supplied with a permanent voltage • Horn
from the battery. • Clockspring
The steering wheel horn switch shares the steering • Horn relay
wheel clockspring circuit with the air-bag circuit. • BJB
Each of these systems work completely
independent of each other. 3. If an obvious cause for an observed or reported
concern is found, correct the cause (if possible)
Inspection and Verification before proceeding to the next step.
4. Retrieve the Diagnostic Trouble Code (DTC)s
1. Verify the customer concern. and refer to the DTC Index Chart.
2. Visually inspect for obvious signs of mechanical
or electrical damage.
Diagnostic Trouble Code (DTC) Index Chart
DTC Description/Condition Possible Source Action
9C5512 Horn relay- circuit short BJB REFER to WDS.
to battery
9C5514 Horn relay - circuit short BJB REFER to WDS.
to ground or open
1. If the cause is still evident, refer to the Symptom
Chart.
Symptom Chart
Symptom Possible Sources Action
• The horn is inoperative • Circuit(s). • GO to Pinpoint Test A.
• Horn.
• Horn relay.
• Clockspring.
• Horn switch.
• BJB
• The horn is always on • Horn relay. • REFER to WDS.
• BJB
• Horn switch.
• Circuit(s).
• Clockspring.
2008.50 Mondeo 1/2009 G548387en
413-06-3 Horn 413-06-3
DIAGNOSIS AND TESTING
Pinpoint Tests
PINPOINT TEST A : THE HORN IS INOPERATIVE
TEST CONDITIONS DETAILS/RESULTS/ACTIONS
A1: CHECK POWER TO THE HORN
1 Disconnect Horn C1RH02.
2 Measure the voltage between the horn C1RH02
pin 2, circuit GBB31B (BU/OG), harness side
V and ground while pressing the horn switch.
• Is the voltage greater than 10 volts?
→ Yes
GO to A2.
→ No
GO to A3.
E75335
A2: CHECK GROUND TO THE HORN
1 Measure the resistance between the horn
C1RH02 pin 1, circuit GD312G (BK/VT), harness
side and ground.
• Is the resistance less than 5 ohms?
→ Yes
INSTALL a new horn. TEST the system for
normal operation.
→ No
REPAIR circuit GD312G (BK/VT). TEST the
E75336 system for normal operation.
A3: CHECK HORN POWER SUPPLY FOR OPEN
1 Disconnect Horn Relay R9.
2 Measure the resistance between the horn relay
R9 pin 5, circuit CBB31B 9BU/OG) harness side
and ground; and horn C1RH02 pin 2, circuit
GBB31B (BU/OG), harness side and ground.
• Is the resistance less than 5 ohms?
→ Yes
INSTALL a new horn relay R9. TEST the
system for normal operation. If the concern
persists, INSTALL a new horn. TEST the
system for normal operation.
E75337
→ No
INSTALL a new BJB. TEST the system for
normal operation.
2008.50 Mondeo 1/2009 G548387en
