2003 FORD MUSTANG air condition

current and historical DTCs through the DLC, using a scan tool. If the air bag indicator does not
function, and the system detects a fault condition, the RCM will signal the GEM to activate an audible
chime. The chime is a series of five sets of five tone bursts. If the chime is heard, the SRS and the air
bag indicator require repair.
LFCs are prioritized. If two or more faults occur at the same time, the fault having the highest priority
will be displayed. After that fault has been corrected, the next highest priority fault will be displayed.
The RCM includes a backup power supply. This feature provides sufficient backup power to deploy the
air bags in the event that the ignition circuit is damaged in a collision before the safing and air bag
sensors determine that deployment is required. The backup power supply will deplete its stored energy
approximately one minute after the battery ground cable is disconnected.
Electrical System
The electrical system that supports the air bag supplemental restraint system (SRS):
zis powered from the battery through the ignition circuit.
z provides the electrical path from the restraints control module (RCM) to the air bag modules.
z provides the electrical path from the RCM to the air bag indicator.
z provides the electrical path from the RCM to the data link connector (DLC).
z provides the electrical path from the RCM to the generic electronic module (GEM).
Sensor WARNING: The restraints control module (RCM) orientation is critical for proper system
operation. If a vehicle equipped with an air bag supplemental restraint system (SRS) has been
involved in a collision in which the center tunnel area has been damaged, inspect the mounting
and bracket for deformation. If damaged, the RCM must be replaced whether or not the air bags
have deployed. In addition, make sure the area of the RCM mounting is restored to its original
condition.
The SRS contains two sensors which are integral to the RCM. The RCM is mounted on the center
tunnel under the instrument panel. Klj . 3 ba
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a
DTC: Diagnostic Trouble Code, retrieved using a scan tool.
b LFC: Lamp fault code, flashed on air bag indicator.
c Tone will sound only if additional DTCs are present.
Inspection and Verification 1. Verify the customer concern by checking the air bag indicator in the instrument cluster. Refer to Prove Out the System in this section.
2. Visually inspect for obvious signs of mechanical and electrical damage using the following chart:
3. If the concern is not visually evident, use the scan tool to retrieve diagnostic trouble codes (DTCs) and perform the on- demand self test.
4. WARNING: The restraint system diagnostic 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.
If the on- demand self test is passed and no DTCs are retrieved, GO to Symptom Chart .
5. If DTCs are retrieved, proceed to the Restraints Control Module (RCM) Diagnostic Trouble Code (DTC) Priority Table.
Symptom Chart — — — No Communication with the Restraints Control Module Go To Pinpoint
Test P .
Visual Inspection Chart Mechanical Electrical
z
Damaged restraints control module (RCM) bracket z
Open fuse(s)
z Damaged wiring harness
z Loose or corroded connectors
z Circuitry open/shorted Symptom Chart
Condition
Possible Sources Action
z Air bag warning indicator is
illuminated continuously z
Circuitry.
z Worn or damaged
connector component.
z RCM.
z Instrument cluster. z
Go To Pinpoint Test A .
z Air bag indicator flashing zAir bag SRS system
fault. z
REFER to DTC
Priority Table.
z Audible tone — DTCs
retrieved z
Air bag SRS system
fault. z
Go To Pinpoint Test N .
z Go To Pinpoint Test O .
z No communication with the zScan Tool. zGo To Pinpoint Klj . 4 ba
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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
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test? This is an intermittent fault.
The fault condition is not
present at this time. GO to
B6
.
B2 INSPECT THE RCM MOUNTING, MOUNTING BRACKET
AND MOUNTING SURFACE z
Remove the RCM. Refer to Restraints Control Module (RCM) in the Removal and Installation portion of this
section.
z Visually inspect the RCM, mounting bracket and mounting
surface for damage, corrosion or dirt.
z Inspect the RCM mounting and make sure that the
retaining bolts are fully seated and tightened correctly.
Refer to Restraints Control Module (RCM) in the Removal
and Installation portion of this section for correct tightening
torque.
z Was a significant amount of corrosion or dirt found,
the RCM mounting bracket attached to the mounting
surface incorrectly or were the three RCM retaining
bolts not fully seated and tightened correctly? Yes
Make sure the RCM,
mounting bracket and
mounting surface are free of
damage, corrosion or dirt and
the three retaining bolts are
fully seated and correctly
tightened. Reattach the RCM
and mounting bracket to the
mounting surface. GO to
B7 .
No
GO to B3 .
B3 CHECK THE RCM HARNESS CONNECTION
z
Check the RCM harness connection.
z Is the RCM harness connector connected to the RCM
correctly? Yes
GO to
B4 .
No
ATTACH the RCM harness
connector correctly. GO to
B7 .
B4 CHECK THE VEHICLE CHASSIS GROUND
z
Measure the resistance between a known good chassis
ground and the mounting surface of the RCM.
z Is the resistance greater than 100 ohms? Yes
REPAIR the chassis
grounding system. GO to
B7 .
No
GO to B5 .
B5 CHECK THE GROUND CIRCUIT 397 (BK/WH) FOR AN
OPEN z
Key in OFF position.
z Disconnect: RCM C2041.
z Measure the resistance between RCM C2041 pin 21,
circuit 397 (BK/WH), harness side and a sheet metal
ground near the RCM.
z Is the resistance greater than 100 ohms? Yes
REPAIR the circuit. GO to
B7
.
No
INSTALL a new RCM. GO to
B7 .
B6 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step B1. Yes Klj . 6 ba
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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
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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
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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
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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
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