pinpoint FORD MUSTANG 2003 Workshop Manual

DIAGNOSIS AND TESTING
Pinpoint Tests —
Air Bag Supplemental Restraint System
(SRS)
Restraint System Diagnostic Tool Warning
WARNING: This tool is for restraint system service only. Remove from vehicle prior to
road use. Failure to remove could result in injury and possible violation of vehicle safety
standards.
Pinpoint Test Note
Do not carry out any pinpoint test unless directed by the Symptom Chart.
Pinpoint Test A: The Air Bag Warning Indicator Is Illuminated Continuously — RCM
Disconnected, Inoperative or Lost/Low Ignition Feed
Normal Operation
NOTE: During normal operation the air bag indicator will be lit continuously for 6 seconds after the
ignition switch is placed in the RUN position and after five cycles of a lamp fault code (LFC) if a fault
exists. Be sure to cycle the ignition switch and look for a 6 second indicator prove- out without LFCs.
The restraints control module (RCM) will communicate diagnostic trouble codes (DTCs) to the scan
tool through the data link connector (DLC). If the scan tool displays NO COMMUNICATION when
retrieving continuous DTCs, Go To Pinpoint Test P to troubleshoot the system.
Possible Causes SECTION 501-
20B: Supplemental Restraint System 2003 Mustang Workshop Manual Special Tool(s)
73III Automotive Meter
105-
R0057 or equivalent Diagnostic Tool, Restraint
System
418-
F088 (105- R0012) Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent scan
tool Klj . 1 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

An air bag indicator that is illuminated continuously can be caused by one of the following:
zworn or damaged shorting bar or camming beam.
z the ignition circuit damaged.
z the RCM disconnected from the vehicle harness.
z a loss of RCM ground circuits.
z the RCM inoperative.
z circuitry.
PINPOINT TEST A: THE AIR BAG WARNING INDICATOR IS
ILLUMINATED CONTINUOUSLY — RCM DISCONNECTED,
INOPERATIVE, OR LOST/LOW IGNITION FEED Test Step Result / Action to
Take A1 CHECK FOR CONTINUOUS OR ON-
DEMAND SELF TEST DTCs z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in this pinpoint
test.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Were any continuous or on- demand self test DTCs retrieved? Yes
If continuous
DTCs were
retrieved, GO to
A3
. If on-
demand
DTCs were
retrieved, GO to
the Restraints
Control Module
(RCM) Diagnostic
Trouble Code
(DTC) Priority
Table in this
section for
pinpoint test
direction.
No
GO to A2 .
A2 CHECK THE RCM CONNECTION
WARNING: If the supplemental restraint system (SRS) is
being serviced, the system must be deactivated and restraint
system diagnostic tools must be installed. Refer to Air Bag Supplemental Restraint System (SRS) in this section.
The air bag restraint system diagnostic tools must be removed
and the air bag modules reconnected when the system is
reactivated to avoid non- deployment in a collision, resulting in
possible personal injury. NOTE: Diagnostics or repairs are not to
be performed on a seat equipped with a seat side air bag with the
seat in the vehicle. Prior to attempting to diagnose or repair a seat
concern when equipped with a seat side air bag, the seat must be
removed from the vehicle and the restraint system diagnostic tools
must be installed in the seat side air bag electrical connectors. The
restraint system diagnostic tools must be removed prior to
operating the vehicle over the road. NOTE: After diagnosing or Yes
GO to
A3 .
No
CONNECT C2041
and engage the
locking tabs. GO
to A7 . Klj . 2 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Test B: LFC 21/DTC B1921 —
RCM Bracket Ground Resistance High
Normal Operation
WARNING: The tightening torque of the restraints control module (RCM) retaining bolts is
critical for proper air bag supplemental restraint system (SRS) operation. Refer to Restraints Control Module (RCM) in this section for correct torque values.
The restraints control module (RCM) monitors the resistance between the ground connections at its
housing and the reference ground at pin 21. If the RCM detects a resistance greater than 100 ohms, it
will store a diagnostic trouble code (DTC) B1921 in memory and flash a lamp fault code (LFC) 21 (or
higher priority code if one exists) on the air bag indicator.
Possible Causes
High resistance between the RCM housing ground and pin ground can be caused by:
zincorrect seating of the RCM retaining bolts.
z incorrect tightening torque of the RCM retaining bolts.
z high resistance on RCM logic ground circuit 397 (BK/WH).
PINPOINT TEST B: LFC 21/DTC B1921 — RCM BRACKET GROUND
RESISTANCE HIGH section for
pinpoint test
direction.
No
RECONNECT the
system.
REACTIVATE the
system. PROVE
OUT the system.
REFER to
Air Bag Supplemental
Restraint System
(SRS) in this
section. CLEAR all
DTCs. Test Step Result / Action to Take
B1 CHECK FOR A HARD OR INTERMITTENT DTC
z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in
this pinpoint test.
z Enter the following diagnostic mode on the diagnostic tool:
On- Demand Self Test.
z Was DTC B1921 retrieved during the on- demand self Yes
This is a hard fault. The fault
condition is still present. This
fault cannot be cleared until it
is corrected and the DTC is
no longer retrieved during the
on-demand self test. GO to
B2 .
No Klj . 5 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Test C: LFC 29/DTC C1414 —
Incorrect Vehicle Identification Code
Normal Operation
The restraints control module (RCM) monitors the electrical state of pins 10, 13 and 14 to determine if
it is installed on the correct vehicle. If the RCM detects an incorrect condition on any of these pins, it
will store a diagnostic trouble code (DTC) C1414 in memory and flash a lamp fault code (LFC) 29 (or
higher priority code if one exists) on the air bag indicator.
Possible Causes
An incorrect vehicle identification code can be caused by:
zan RCM installed on the wrong vehicle.
z an incorrectly programmed RCM.
z vehicle ID pins not connected as expected.
PINPOINT TEST C: LFC 29/DTC C1414 — INCORRECT VEHICLE
IDENTIFICATION CODE z
Was the continuous DTC retrieved during Step B1 an
intermittent fault? CHECK for causes or
intermittent high resistance on
circuit 397 (BK/WH). Attempt
to recreate the hard fault by
flexing the wire harness and
cycling the ignition key
frequently. REPAIR any
intermittent concerns found.
GO to
B7 .
No
GO to B7 .
B7 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step B1.
z Were any continuous DTCs retrieved during Step B1? Yes
Do not clear any DTCs until
all DTCs have been resolved.
GO to the Restraints Control
Module (RCM) Diagnostic
Trouble Code (DTC) Priority
Table in this section for
pinpoint test direction.
No
RECONNECT the system.
REACTIVATE the system.
PROVE OUT the system.
REFER to
Air Bag Supplemental Restraint
System (SRS) in this section.
CLEAR all DTCs. Test Step Result / Action to
Take C1 CHECK FOR A HARD OR INTERMITTENT DTC Klj . 7 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in this pinpoint
test.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC C1414 retrieved during the on- demand self test? Yes
This is a hard
fault. The fault
condition is still
present. This fault
cannot be cleared
until it is corrected
and the DTC is no
longer retrieved
during the on-
demand self test.
GO to
C2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
C5 .
C2 CHECK THE VEHICLE IDENTIFICATION PINS NO. 1 AND NO. 2
WARNING: If the supplemental restraint system (SRS) is
being serviced, the system must be deactivated and restraint
system diagnostic tools must be installed. Refer to Air Bag Supplemental Restraint System (SRS) in this section.
The air bag restraint system diagnostic tools must be removed
and the air bag modules reconnected when the system is
reactivated to avoid non- deployment in a collision, resulting in
possible personal injury. NOTE: Diagnostics or repairs are not to be
performed on a seat equipped with a seat side air bag with the seat in
the vehicle. Prior to attempting to diagnose or repair a seat concern
when equipped with a seat side air bag, the seat must be removed
from the vehicle and the restraint system diagnostic tools must be
installed in the seat side air bag electrical connectors. The restraint
system diagnostic tools must be removed prior to operating the
vehicle over the road. NOTE: After diagnosing or repairing an SRS,
the restraint system diagnostic tools must be removed before
operating the vehicle over the road. NOTE: After diagnosing or
repairing a seat system, the restraint system diagnostic tools must
be removed before operating the vehicle over the road. NOTE:
The SRS must be fully operational and free of faults before releasing
the vehicle to the customer. NOTE: For this vehicle application, RCM
C2041 pins 10 and 13 should be open circuited.
z Key in OFF position.
z Deactivate the system. Refer to Air Bag Supplemental Restraint System (SRS) in the Diagnosis and Testing portion of this section.
z Key in OFF position.
z Disconnect: RCM C2041.
z Make sure the RCM C2041 pin 10 and pin 13 connector slots are
empty and no connection is made when connected to the RCM.
z Are the RCM C2041 pin 10 and pin 13 connector slots empty? Yes
GO to
C3 .
No
REPAIR any
concern found at
the RCM C2041
pin 10 and pin 13
connector slots.
GO to C6 .
C3 CHECK THE VEHICLE IDENTIFICATION PIN NO. 3
NOTE:
For this vehicle application, RCM C2041 pin 14, circuit 611
(WH/OG) should be connected to ignition voltage.
z Measure the voltage at RCM C2041 pin 14, circuit 611 (WH/OG),
harness side and ground. Yes
GO to
C4 .
No
REPAIR the
circuit. GO to C6 . Klj . 8 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

z
Is the voltage greater than 10 volts? C4 CHECK THE RCM PROGRAMMED VEHICLE ID
z
Enter the following diagnostic mode on the diagnostic tool: PID/Data
Monitor and Record.
z Select PID VID No. 1, VID No. 2, and VID No. 3.
z Was vehicle ID No. 1 and vehicle ID No. 2 no connect and vehicle
ID No. 3 ignition? Yes
GO to
C5 .
No
INSTALL a new
RCM. GO to C6 .
C5 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step C1.
z Was the continuous DTC retrieved during Step C1 an intermittent
fault or were you directed to this step from Step C4? Yes
CHECK for
causes of an
intermittent open
on circuit 611
(WH/OG). Attempt
to recreate the
hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
C6 .
No
GO to C6 .
C6 CHECK FOR ADDITIONAL DTCs
z
Refer to continuous DTCs recorded during Step C1.
z Were any continuous DTCs retrieved during Step C1? Yes
Do not clear any
DTCs until all
DTCs have been
resolved. GO to
the Restraints
Control Module
(RCM) Diagnostic
Trouble Code
(DTC) Priority
Table in this
section for
pinpoint test
direction.
No
RECONNECT the
system.
REACTIVATE the Klj . 9 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Test D: LFC 15/DTC B 1887—
Driver Air Bag Circuit Shorted to Ground
Normal Operation
The restraints control module (RCM) checks for driver air bag circuit shorts to ground by monitoring the
voltage of circuits 614 (GY/OG) and 615 (GY/WH) at pins 3 and 4. If the RCM detects a short to
ground on either of these pins, it will store a diagnostic trouble code (DTC) B1887 in memory and flash
a lamp fault code (LFC) 15 (or higher priority code if one exists) on the air bag indicator.
Possible Causes
A driver air bag circuit short to ground can be caused by:
za short to ground on circuit 614 (GY/OG).
z a short to ground on circuit 615 (GY/WH).
z a short to ground on the clockspring (14A664).
z a short to ground on the driver air bag module.
z an RCM internal concern.
PINPOINT TEST D: LFC 15/DTC B1887 — DRIVER AIR BAG CIRCUIT
SHORTED TO GROUND system. PROVE
OUT the system.
REFER to
Air Bag Supplemental
Restraint System
(SRS) in this
section. CLEAR
all DTCs. Test Step Result / Action to
Take D1 CHECK FOR A HARD OR INTERMITTENT DTC
z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in this
pinpoint test.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1887 retrieved during the on- demand self test? Yes
This is a hard fault.
The fault condition
is still present. This
fault cannot be
cleared until it is
corrected and the
DTC is no longer
retrieved during the
on-
demand self
test. GO to D2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
D5 . Klj . 10 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Test E: LFC 15/DTC B1916 —
Driver Air Bag Circuit Shorted to Battery or Ignition
Normal Operation
The restraints control module (RCM) checks for driver air bag circuit shorts to battery or ignition by
monitoring the voltage of circuit 614 (GY/OG) and 615 (GY/WH) at pins 3 and 4. If the RCM detects a
short to battery or ignition on either of these pins, it will store a diagnostic trouble code (DTC) B1916 in
memory and flash a lamp fault code (LFC) 15 (or higher priority code if one exists) on the air bag
indicator.
Possible Causes D5 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step D1.
z Was the continuous DTC retrieved during Step D1 an
intermittent fault? Yes
CHECK for causes
of intermittent short
to ground on circuit
614 (GY/OG),
circuit 615
(GY/WH), and the
clockspring
assembly. Attempt
to recreate the hard
fault by flexing the
wire harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
D6 .
No
GO to D6 .
D6 CHECK FOR ADDITIONAL DTCs
z
Refer to continuous DTCs recorded during Step D1.
z Were any continuous DTCs retrieved during Step D1? Yes
Do not clear any
DTCs until all DTCs
have been
resolved. GO to the
Restraints Control
Module (RCM)
Diagnostic Trouble
Code (DTC) Priority
Table in this section
for pinpoint test
direction.
No
RECONNECT the
system.
REACTIVATE the
system. PROVE
OUT the system.
REFER to
Air Bag Supplemental
Restraint System
(SRS) in this
section. CLEAR all
DTCs. Klj . 12 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

A driver air bag circuit short to battery or ignition can be caused by:
za short to battery or ignition on circuit 614 (GY/OG).
z a short to battery or ignition on circuit 615 (GY/WH).
z a short to battery or ignition on the clockspring.
z a short to battery or ignition on the driver air bag module.
z an RCM internal concern.
PINPOINT TEST E: LFC 15/DTC B1916 — DRIVER AIR BAG CIRCUIT
SHORTED TO BATTERY OR IGNITION Test Step Result / Action to
Take E1 CHECK FOR A HARD OR INTERMITTENT DTC
z
Key in OFF position.
z Connect the diagnostic tool. Scan Tool
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool:
Retrieve/Clear Continuous DTCs.
z Retrieve and record any continuous DTCs for use later in this
pinpoint test.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1916 retrieved during the on- demand self test? Yes
This is a hard fault.
The fault condition
is still present. This
fault cannot be
cleared until it is
corrected and the
DTC is no longer
retrieved during the
on-
demand self
test. GO to E2 .
No
This in an
intermittent fault.
The fault condition
is not present at this
time. GO to E5 .
E2 CHECK THE DRIVER AIR BAG MODULE
WARNING: If the supplemental restraint system (SRS) is
being serviced, the system must be deactivated and restraint
system diagnostic tools must be installed. Refer to Air Bag Supplemental Restraint System (SRS) in this section.
The air bag restraint system diagnostic tools must be removed
and the air bag modules reconnected when the system is
reactivated to avoid non- deployment in a collision, resulting in
possible personal injury. NOTE: Diagnostics or repairs are not to
be performed on a seat equipped with a seat side air bag with the
seat in the vehicle. Prior to attempting to diagnose or repair a seat
concern when equipped with a seat side air bag, the seat must be
removed from the vehicle and the restraint system diagnostic tools
must be installed in the seat side air bag electrical connectors. The
restraint system diagnostic tools must be removed prior to
operating the vehicle over the road. NOTE: After diagnosing or
repairing an SRS, the restraint system diagnostic tools must be
removed before operating the vehicle over the road. NOTE:
After diagnosing or repairing a seat system, the restraint system
diagnostic tools must be removed before operating the vehicle Yes
GO to
E3 .
No
INSTALL a new
driver air bag
module. GO to E6 . Klj . 13 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Pinpoint Test F: LFC 16/DTC B1888 —
Passenger Air Bag Circuit Shorted to Ground
Normal Operation
The restraints control module (RCM) checks for passenger air bag circuit shorts to ground by
monitoring the voltage of circuits 607 (LB/OG) and 616 (PK/BK) at pins 6 and 7. If the RCM detects a
short to ground on either of these pins, it will store a diagnostic trouble code (DTC) B1888 in memory
and flash a lamp fault code (LFC) 16 (or higher priority code if one exists) on the air bag indicator.
Possible Causes
A passenger air bag circuit short to ground can be caused by:
za short to ground on circuit 607 (LB/OG).
z a short to ground on circuit 616 (PK/BK).
z a short to ground on the passenger air bag module.
z an RCM internal concern.
PINPOINT TEST F: LFC 16/DTC B1888 — PASSENGER AIR BAG
CIRCUIT SHORTED TO GROUND to E6 .
No
GO to E6 .
E6 CHECK FOR ADDITIONAL DTCs
z
Refer to continuous DTCs recorded during Step E1.
z Were any continuous DTCs retrieved during Step E1? Yes
Do not clear any
DTCs until all DTCs
have been
resolved. GO to the
Restraints Control
Module (RCM)
Diagnostic Trouble
Code (DTC) Priority
Table in this section
for pinpoint test
direction.
No
RECONNECT the
system.
REACTIVATE the
system. PROVE
OUT the system.
REFER to
Air Bag Supplemental
Restraint System
(SRS) in this
section. CLEAR all
DTCs. Test Step Result / Action to
Take Klj . 15 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...