2003 FORD MUSTANG wiring

4. If the concern remains after the inspection, connect the scan tool to the data link connector
(DLC) located beneath the instrument panel and select the vehicle to be tested from the scan
tool menu. If the scan tool does not communicate with the vehicle:
zcheck that the program card is correctly installed.
z check the connections to the vehicle.
z check the ignition switch position.
5. If the scan tool still does not communicate with the vehicle, refer to the scan tool manual.
6. Carry out the DATA LINK DIAGNOSTIC TEST. If the scan tool responds with: zCKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section 418 -
00 .
z NO RESP/NOT EQUIP for GEM, go to Pinpoint Test A.
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.
7. If the DTCs retrieved are related to the concern, go to GEM Diagnostic Trouble Code (DTC) Index to continue diagnostics.
8. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics.
GEM Diagnostic Trouble Code (DTC) Index Visual Inspection Chart Mechanical Electrical
z
Switch(es) z
CJB Fuses:
„7 (20A)
„ 32 (15A)
„ 39 (5A)
z Wiring harness
z Connections
z Lamps
z Circuitry
GEM Diagnostic Trouble Code (DTC) Index DTC Description Source Action
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 .
B1342 ECU Is Defective GEM CLEAR the DTC. Retrieve the DTCs. If DTC B1342 is
retrieved, INSTALL a new GEM. For additional information, REFER to Section 419 - 10 .
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 . Klj . 3 ba
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DIAGNOSIS AND TESTING
Daytime Running Lamps (DRL)
Refer to Wiring Diagrams Cell
97 , Daytime Running Lamps for schematic and connector information.
Principles of Operation
Daytime Running Lamps (DRL)
The daytime running lamps (DRL) system operates the low beam headlamps at a reduced intensity.
The DRL module (15A270) supplies pulse width modulated (PWM) voltage, approximately 75%- 92%
of battery voltage, to the low beam headlamps when the following conditions are met:
zThe parking brake control is released.
z The high beam headlamps are disabled.
z The ignition switch (11572) is in the RUN position.
The DRL module remains enabled when the low beam headlamps are turned on.
Inspection and Verification 1. Verify the customer concern by operating the system.
2. Visually inspect for obvious signs of mechanical and electrical damage.
3. Verify the headlamps are operating correctly. Correct any concerns before proceeding to the
SECTION 417-
04: Daytime Running Lamps 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter or
equivalent
105-
R0057
Visual Inspection Chart Mechanical Electrical
z
Damaged DRL module
z Damaged parking brake signal switch and
bracket (15A851) z
Blown battery junction box (BJB) Maxi-
Fuse FOG+DRL (20A)
z Damaged wiring harness
z Loose or corroded connection
z Damaged DRL module
z Damaged parking brake signal switch and
bracket Klj . 1 ba
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PINPOINT TEST C: THE DAYTIME RUNNING LAMPS ARE ON WITH
THE IGNITION SWITCH OFF z
Do the DRL turn off? B2 CHECK THE PARKING BRAKE SWITCH SIGNAL CIRCUIT
z
Key in OFF position.
z Disconnect: DRL Module C1030.
z Measure the resistance between parking brake switch C306,
Circuit 22 (LB/BK), harness side and DRL module C1030 Pin
6, Circuit 22 (LB/BK), harness side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new DRL
module. REFER to
Module
— Daytime
Running Lamps (DRL) .
TEST the system for
normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation. Test Step Result / Action to Take
C1 CHECK THE IGNITION SWITCH INPUT TO THE DRL
MODULE FOR VOLTAGE z
Key in OFF position.
z Disconnect: DRL Module C1030.
z Measure the voltage between DRL module C1030 Pin 3,
Circuit 298 (VT/OG), harness side and ground.
z Is voltage indicated? Yes
GO to
C2 .
No
INSTALL a new DRL module.
REFER to Module — Daytime
Running Lamps (DRL) . TEST
the system for normal
operation. C2 CHECK THE IGNITION SWITCH
z
Check the ignition switch; refer to the Wiring Diagrams
Cell 149.
z Is the ignition switch OK? Yes
REPAIR Circuit 298 (VT/OG)
for short to battery. TEST the
system for normal operation.
No
INSTALL a new ignition switch.
REFER to
Section 211 - 05 .
TEST the system for normal
operation. Klj . 5 ba
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DIAGNOSIS AND TESTING
Communications Network
Refer to Wiring Diagrams Cell
14 , Multiplex Communication Network for schematic and connector
information.
Principles of Operation
The vehicle has two module communications networks. The standard corporate protocol (SCP) which
is an unshielded twisted pair cable (data bus plus, Circuit 914 [TN/OG] and data bus minus, Circuit 915
[PK/LB]), and the international standards organization (ISO) 9141 network which is a single wire
(Circuit 70 [LB/WH]). The diagnostic tool can connect to both networks through the data link connector
(DLC). This makes diagnosis and testing of these systems easier by allowing one smart tester to be
able to diagnose and control any module on the two networks from one connector. The DLC can be
found under the instrument panel between the steering column and the radio.
The ISO 9141 communication network does not permit inter- module communication. When the
diagnostic tool communicates to modules on the ISO 9141 communication network, the diagnostic tool
must ask for all information; the modules cannot initiate communications.
The SCP network will remain operational even with the severing of one of the bus wires.
Communications will also continue if one of the bus wires is shorted to ground or battery positive
voltage (B+) or if some, but not all, termination resistors are lost.
Unlike the SCP communication network, the ISO 9141 communication network will not function if the
wire is shorted to chassis ground or battery positive voltage (B+). Also, if one of the modules on the
ISO 9141 network loses power or shorts internally, communications to that module will fail.
The powertrain control module (PCM) is on the SCP communication network. The PCM controls the
engine for better fuel economy, emissions control, and failure mode detection and storage. Refer to
Powertrain Control/Emissions Diagnosis (PC/ED) manual Section 3 for diagnosis and testing of the
PCM.
The restraint control module (RCM) is on the ISO 9141 network. The RCM controls the deployment of
the air bags based on sensor input. For additional information, refer to Section 501 - 20B .
SECTION 418-
00: Module Communications Network 2003 Mustang Workshop Manual Special Tool(s)
73 Digital Multimeter or
equivalent
105-
R0051 Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool Klj . 1 ba
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The generic electronic module (GEM) is on the ISO 9141 network. The GEM module controls a variety
of systems including one touch down windows, wipers, perimeter anti-
theft, and warning chimes. For
additional information, refer to Section 419 - 10 .
The anti- lock brake control module communicates over the ISO 9141 communication network when
not equipped with traction control and communicates over the SCP communication network when it is
equipped with the traction control option. The anti- lock brake control module controls the brake
pressure to the four wheels to keep the vehicle under control while braking. For additional information
on anti- lock brake control module without traction control, refer to Section 206 - 09A . For additional
information on anti- lock brake control module with traction control, refer to Section 206 - 09B .
The instrument cluster is on the SCP communication network. The instrument cluster displays driver
information. The instrument cluster incorporates the PATS control module functions. For additional
information on the PATS system, refer to Section 419 - 01 . For additional information on the instrument
cluster, refer to Section 413 - 01 .
Inspection and Verification 1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.
3. If the concern remains after the inspection, connect diagnostic tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from diagnostic
tool menu. If diagnostic tool does not communicate with the vehicle:
zcheck that the program card is correctly installed.
z check that the correct version of the program card is installed.
z check the connections to the vehicle.
z check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, go to Pinpoint Test H. 4. Go to Pinpoint Test PC.
System Precheck Visual Inspection Chart Electrical
z
Central junction box (CJB) Fuse 31 (5A)
z Damaged wiring harness
z Loose or corroded connections
z Anti- lock brake control module without traction control (optional)
z Anti- lock brake control module with traction control (optional)
z Generic electronic module (GEM)
z Restraint control module (RCM)
z Powertrain control module (PCM)
z Instrument cluster Klj . 2 ba
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z
Was the result retrieved ABS: NO RESPONSE ON
CKT914 (BUS+)? A3 CHECK FOR OPEN BETWEEN DLC C251 AND ANTI-
LOCK BRAKE CONTROL MODULE C135 — CIRCUIT 914
(TN/OG) z
Key in OFF position.
z Disconnect the diagnostic tool.
z Disconnect: Anti- Lock Brake Control Module C135.
z Measure the resistance between anti- lock brake control
module C135 Pin 30, Circuit 914 (TN/OG), harness side
and DLC C251 Pin 2, Circuit 914 (TN/OG), harness
side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new anti-
lock brake
control module. REFER to
Section 206 - 09B . TEST the
system for normal operation.
No
GO to A4 .
A4 CHECK CIRCUIT 914 (TN/OG) BETWEEN DLC C251
AND IN- LINE C144 FOR OPEN z
Disconnect: In- Line C144.
z Check in-line C144 for damage; repair as necessary.
z Measure the resistance between in- line C144 Pin 6,
Circuit 914 (TN/OG), harness side and DLC C251 Pin 2,
Circuit 914 (TN/OG), harness side.
z Is the resistance less than 5 ohms? Yes
REPAIR Circuit 914 (TN/OG)
between anti-
lock brake control
module C135 and in- line C144.
For additional information,
REFER to Communication Circuit Wiring Repair . TEST the
system for normal operation.
No
GO to A5 .
A5 CHECK CIRCUIT 914 (TN/OG) BETWEEN DLC C251
AND IN- LINE C215 FOR OPEN z
Disconnect: In- Line C215.
z Check in-line C215 for damage; repair as necessary.
z Measure the resistance between in- line C215 Pin 10,
Circuit 914 (TN/OG), harness side and DLC C251 Pin 2,
Circuit 914 (TN/OG), harness side. Yes
REPAIR Circuit 914 (TN/OG)
between in-
line C144 and in- line
C215. For additional
information, REFER to
Communication Circuit Wiring Repair . TEST the system for
normal operation.
No
REPAIR Circuit 914 (TN/OG)
between DLC C251 and in- line
C215. For additional Klj . 5 ba
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z
Is the resistance less than 5 ohms? information, REFER to
Communication Circuit Wiring
Repair . TEST the system for
normal operation. A6 CHECK FOR OPEN BETWEEN DLC C251 AND ANTI-
LOCK BRAKE CONTROL MODULE C135 — CIRCUIT 915
(PK/LB) z
Key in OFF position.
z Disconnect the diagnostic tool.
z Measure the resistance between anti- lock brake control
module C135 Pin 29, Circuit 915 (PK/LB), harness side
and DLC C251 Pin 10, Circuit 915 (PK/LB), harness
side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new anti-
lock brake
control module. REFER to
Section 206 - 09B . TEST the
system for normal operation.
No
GO to A7 .
A7 CHECK CIRCUIT 915 (PK/LB) BETWEEN DLC C251
AND IN- LINE C144 FOR OPEN z
Disconnect: In- Line C144.
z Check in-line C144 for damage; repair as necessary.
z Measure the resistance between in- line C144 Pin 13,
Circuit 915 (PK/LB), harness side and DLC C251 Pin
10, Circuit 915 (PK/LB), harness side.
z Is the resistance less than 5 ohms? Yes
REPAIR Circuit 915 (PK/LB)
between anti-
lock brake control
module C135 and in- line C144.
For additional information,
REFER to Communication Circuit Wiring Repair . TEST the
system for normal operation.
No
GO to A8 .
A8 CHECK CIRCUIT 915 (PK/LB) BETWEEN DLC C251
AND IN- LINE C215 FOR OPEN z
Disconnect: In- Line C215.
z Check in-line C215 for damage; repair as necessary.
z Measure the resistance between in- line C215 Pin 13,
Circuit 915 (PK/LB), harness side and DLC C251 Pin Yes
REPAIR Circuit 915 (PK/LB)
between in-
line C144 and in- line
C215. For additional Klj . 6 ba
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10, Circuit 915 (PK/LB), harness side.
z Is the resistance less than 5 ohms? information, REFER to
Communication Circuit Wiring
Repair . TEST the system for
normal operation.
No
REPAIR Circuit 915 (PK/LB)
between DLC C251 and in- line
C215. For additional
information, REFER to
Communication Circuit Wiring Repair . TEST the system for
normal operation. A9 CHECK FOR OPEN BETWEEN THE DLC C251 AND
ANTI- LOCK BRAKE CONTROL MODULE C135 — CIRCUIT
70 (LB/WH) z
Key in OFF position.
z Disconnect: Anti- Lock Brake Control Module C135.
z Inspect anti- lock brake control module C135 for
damage, repair as necessary.
z Measure the resistance between anti- lock brake control
module C135 Pin 24, Circuit 70 (LB/WH), harness side
and DLC C251 Pin 7, Circuit 70 (LB/WH), harness side.
z Is the resistance less than 5 ohms? Yes
INSTALL a new anti-
lock brake
control module. REFER to
Section 206 - 09A . TEST the
system for normal operation.
No
GO to A10 .
A10 CHECK FOR OPEN BETWEEN THE DLC C251 AND
IN- LINE C140 z
Disconnect: In- Line C140.
z Inspect in- line C140 for damage, repair as necessary.
z Measure the resistance between in- line C140 Pin 7,
Circuit 70 (LB/WH), harness side and DLC C251 Pin 7,
Circuit 70 (LB/WH), harness side.
z Is the resistance less than 5 ohms? Yes
REPAIR Circuit 70 (LB/WH)
between in-
line C140 and anti-
lock brake control module C135.
TEST the system for normal
operation.
No
GO to A11 .
A11 CHECK FOR OPEN BETWEEN THE DLC C251 AND
IN- LINE C314 z
Disconnect: In- Line C314.
z Inspect in- line C314 for damage, repair as necessary. Yes
REPAIR Circuit 70 (LB/WH) Klj . 7 ba
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