2003 FORD MUSTANG relay

PINPOINT TEST E: INSUFFICIENT A/C COOLING C294c-
3, circuit 348 (PK), harness side and ground.
z Is there voltage present? No
INSTALL a new function
selector switch. REFER to
Section 412
- 04 . TEST the
system for normal operation. D5 CHECK FOR A SHORTED CLUTCH INPUT
z
Key in OFF position.
z Disconnect: A/C Clutch C100.
z Key in ON position.
z Measure for voltage at the A/C clutch C100, circuit 347
(BK/YE), harness side and ground.
z Is there voltage present? Yes
INSTALL a new constant
control relay module. TEST the
system for normal operation.
No
CHECK the clutch air gap.
REFER to
Air Conditioning (A/C) Clutch Air Gap
Adjustment .
Test Step Result / Action to Take
E1 CHECK THE CENTER A/C REGISTER DISCHARGE
TEMPERATURE z
Carry out the refrigerant system tests. Refer to
Refrigerant System Tests in this section.
z Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for center A/C register discharge
temperature.
z Is the intersection of the two lines within the upper
and lower limits? Yes
The tests indicate that the
system is functioning normally.
No
GO to
E2 . Klj . 25 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

z
air bag warning indicator
z BRAKE warning indicator
z charging system indicator
z fail safe cooling warning indicator
z low coolant level indicator
z low fuel warning indicator
z traction control indicator
Instrument Cluster Replacement
When it is necessary to install a new instrument cluster, contact the Instrument Cluster Program.
Gauge Indication Systems
Tachometer
Engine rpm information is relayed to the instrument cluster from the powertrain control module (PCM)
over the standard corporate protocol (SCP) network.
Speedometer
The instrument cluster receives the vehicle speed signal from the PCM over the SCP network and
displays it on the speedometer gauge. If the instrument cluster receives no vehicle speed signal after
one second, the speedometer defaults to 0.0 km/h (0.0 mph).
Odometer
The instrument cluster receives an odometer message from the PCM and stores the mileage in
memory. When the instrument cluster fails to receive the odometer message for more than two
seconds, the odometer will display dashes.
Fuel Gauge
The fuel sender is hardwired to the fuel gauge. When the instrument cluster fails to receive the fuel
level signal for more than 33 seconds, the fuel level gauge will move below E (empty). If the fuel level
signal operates correctly for more than 33 seconds, the fuel gauge will return to the correct position.
Fuel fills of less than 9.5 liters (2.5 gallons) require at least 10 minutes to update the fuel gauge
indication.
Engine Coolant Temperature Gauge
Engine coolant temperature information is received by the instrument cluster from the PCM over the
SCP network. Engine coolant temperatures above 121°C (250°F) will cause the gauge to indicate
above the normal band. If the engine coolant temperature information is missing or invalid for five
seconds, the temperature gauge will indicate below the cold (C) position.
Voltage Gauge (except Cobra)
The voltage gauge displays the system voltage as measured at the instrument cluster run input. Boost Gauge (Cobra only) Klj . 2 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

GEM Diagnostic Trouble Code (DTC) Index
DTC Description Source Action
B1218 Horn Relay Coil Circuit Short to
VBatt GEM REFER to
Section 501 - 14B .
B1312 Lamp Headlamp Input Circuit
Short to Battery GEM REFER to
Section 413 - 09 .
B1317 Battery Voltage High GEM REFER to
Section 414 - 00 .
B1318 Battery Voltage Low GEM REFER to
Section 414 - 00 .
B1322 Driver Door Ajar Circuit Short to
Ground GEM REFER to
Section 417 - 02 .
B1330 Passenger Door Ajar Circuit
Short to Ground GEM REFER to
Section 417 - 02 .
B1334 Decklid Ajar Rear Door Circuit
Short to Ground GEM REFER to
Section 417 - 02 .
B1339 Chime Input Request Circuit
Short to Battery GEM REFER to
Section 413 - 09 .
B1340 Chime Input Request Circuit
Short to Ground GEM REFER to
Section 413 - 09 .
B1342 ECU is Defective GEM Clear the DTCs. Retrieve the DTCs. If DTC B1342
is retrieved, INSTALL a new GEM. REFER to Section 419 - 10 .
B1353 Ignition Key-
In Circuit Open GEM REFER to
Section 413 - 09 .
B1359 Ignition Run/Acc Circuit Failure GEM REFER to
Section 211 - 05 .
B1396 Power Door Lock Circuit Short
to Battery GEM REFER to
Section 501 - 14B .
B1397 Power Door Unlock Circuit
Short to Battery GEM REFER to
Section 501 - 14B .
B1405 Driver Power Window Down
Circuit Short to Battery GEM REFER to
Section 501 - 11 .
B1408 Driver Power Window Up
Circuit Short to Battery GEM REFER to
Section 501 - 11 .
B1426 Lamp Safety Belt Circuit Short
to Battery GEM Go To Pinpoint Test K .
B1428 Lamp Safety Belt Circuit Failure GEM Go To Pinpoint Test K .
B1431 Wiper Brake/Run Relay Circuit
Failure GEM REFER to
Section 501 - 16 .
B1432 Wiper Brake/Run Relay Circuit
Short to Battery GEM REFER to
Section 501 - 16 .
B1434 Wiper Hi/Low Speed Relay Coil
Circuit Failure GEM REFER to
Section 501 - 16 .
B1436 Wiper Hi/Low Speed Relay Coil
Circuit Short to Battery GEM REFER to
Section 501 - 16 .
B1438 Wiper Mode Select Switch
Circuit Failure GEM REFER to
Section 501 - 16 .
B1441 Wiper Mode Select Switch
Circuit Short to Ground GEM REFER to
Section 501 - 16 . Klj . 8 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Symptom Chart B1446 Wiper Park Sense Circuit
Failure GEM REFER to
Section 501 - 16 .
B1448 Wiper Park Sense Circuit Short
to Battery GEM REFER to
Section 501 - 16 .
B1450 Wiper Wash/Delay Switch
Circuit Failure GEM REFER to
Section 501 - 16 .
B1453 Wiper Wash/Delay Switch
Circuit Short to Ground GEM REFER to
Section 501 - 16 .
B1458 Wiper Washer Pump Motor
Relay Circuit Failure GEM REFER to
Section 501 - 16 .
B1460 Wiper Washer Pump Motor
Relay Coil Circuit Short to Battery GEM REFER to
Section 501 - 16 .
B1462 Safety Belt Switch Circuit
Failure GEM REFER to
Section 413 - 09 .
B1466 Wiper Hi/Low Speed Not
Switching GEM REFER to
Section 501 - 16 .
B1473 Wiper Low Speed Circuit Motor
Failure GEM REFER to
Section 501 - 16 .
B1476 Wiper High Speed Circuit Motor
Failure GEM REFER to
Section 501 - 16 .
B1551 Decklid Release Circuit Failure GEM REFER to
Section 501 - 14B .
B1553 Decklid Release Circuit Short to
Battery GEM REFER to
Section 501 - 14B .
B1555 Ignition Run/Start Circuit
Failure GEM REFER to
Section 211 - 05 .
B1687 Lamp Dome Input Circuit Short
to Battery GEM REFER to
Section 417 - 02 .
B2486 Parklamp Output Relay Driver
Circuit Failure GEM REFER to
Section 419 - 01 .
B2488 Parklamp Output Relay Driver
Short to Battery GEM REFER to
C1189 Brake Fluid Level Sensor Input
Short Circuit to Ground GEM Go To Pinpoint Test O .
C1223 Lamp Brake Warning Output
Circuit Failure GEM Go To Pinpoint Test O .
C1225 Lamp Brake Warning Output
Circuit Short to Battery GEM Go To Pinpoint Test O .
Symptom Chart Condition
Possible Sources Action
z No communication with
the generic electronic
module (GEM) z
Central junction
box (CJB) fuse
(s):
„7 (15A).
„ 39 (5A).
„ 43 z
Go To Pinpoint Test W Klj . 9 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
52003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...