FORD MUSTANG 2003 Workshop Manual

Pinpoint Test M: DTC B1891 —
Air Bag Tone Warning Indicator Circuit Shorted to Battery or
Ignition
Normal Operation
The restraints control module (RCM) monitors its connection to the generic electronic module (GEM) at
pin 10. This connection is used to signal a chime if the air bag indicator is inoperative and another SRS
fault exists. If the RCM detects a short to battery or ignition on the connection to the GEM, it will store
a diagnostic trouble code (DTC) B1891 in memory.
Possible Causes z
Is the voltage less than 1.0 volt? L5 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step L1.
z Was the continuous DTC retrieved during Step L1 an
intermittent fault? Yes
CHECK for causes
of intermittent
short to ground or
open on circuit
1083 (LB/BK).
Attempt to recreate
the hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
L6 .
No
GO to L6 .
L6 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step L1.
z Were any continuous DTCs retrieved during Step L1? 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 . 34 ba
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An air bag tone warning indicator circuit short to battery or ignition can be caused by:
za short to battery or ignition on circuit 1083 (LB/BK).
z a damaged or inoperative GEM.
z an RCM internal concern.
PINPOINT TEST M: DTC B1891 — AIR BAG TONE WARNING
INDICATOR CIRCUIT SHORTED TO BATTERY OR IGNITION Test Step Result / Action to
Take M1 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 B1891 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
M2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
M4 .
M2 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT
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. Yes
GO to
M3 .
No
REPAIR the
circuit. GO to M5 . Klj . 35 ba
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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 Disconnect: GEM C201e.
z Key in ON position.
z Measure the voltage between RCM C2041 pin 26, circuit 1083
(LB/BK), harness side and ground.
z Is the voltage less than 0.2 volt? M3 CHECK THE AIR BAG TONE WARNING INDICATOR
z
Key in OFF position.
z Connect: GEM C201e.
z Key in ON position.
z Jumper RCM C2041 pin 26, circuit 1083 (LB/BK), harness side to
ground.
z Does the GEM generate a tone? Yes
INSTALL a new
RCM. GO to
M5 .
No
INSTALL a new
GEM. GO to M5 .
M4 CHECK FOR AN INTERMITTENT FAULT
z
Refer to continuous DTCs recorded during Step M1.
z Was the continuous DTC retrieved during step M1 an
intermittent fault? Yes
Check for causes
of intermittent
short to ground or
open on circuit
1083 (LB/BK).
Attempt to recreate
the hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
M5 .
No
GO to M5 . Klj . 36 ba
462003 Mustang Workshop Manual
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Pinpoint Test N: DTC B1869 —
Air Bag Indicator Inoperative
Normal Operation
The air bag indicator is designed to illuminate for 6 (+/- 2) seconds when the ignition switch is turned to
the RUN position. This initial 6 seconds of illumination is considered normal operation and is called
proveout of the air bag indicator. The air bag indicator is then used to warn the driver that there is a
fault in the air bag supplemental restraint system (SRS).
The restraints control module (RCM) monitors the air bag indicator for open and short to ground
conditions. If the RCM detects an open or short to ground condition on the air bag indicator circuit, it
will store a diagnostic trouble code (DTC) B1869 in memory.
If the RCM detects an air bag indicator failure in addition to another SRS failure, the RCM will send a
signal to the generic electronic module (GEM) to produce five sets of five tone bursts.
Possible Causes
An air bag indicator inoperative condition can be caused by:
za damaged wiring on circuit 608 (BK/YE).
z a damaged or burned out air bag indicator.
z worn or damaged instrument cluster.
z an RCM internal concern.
PINPOINT TEST N: DTC B1869 — AIR BAG INDICATOR INOPERATIVE M5 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step M1.
z Were any continuous DTCs retrieved during Step M1? 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 . 37 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

Test Step Result / Action to
Take N1 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 B1869 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
N2 .
No
This is an
intermittent fault.
The fault
conditions not
present at this
time. GO to N5 .
N2 CHECK THE RCM
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.
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 Measure the resistance between RCM C2041 pin 20, component
side and a known good chassis ground. Yes
INSTALL a new
RCM. GO to
N6 .
No
GO to N3 . Klj . 38 ba
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z
Is the resistance less than 10 ohms? N3 CHECK CIRCUIT 608 (BK/YE) FOR A SHORT TO GROUND
z
Key in OFF position.
z Disconnect: Instrument Cluster C220a.
z Measure the resistance to ground at instrument cluster C220a pin 12,
circuit 608 (BK/YE).
z Is the resistance less than 100 ohms? Yes
REPAIR the
circuit. GO to
N6 .
No
GO to N4 .
N4 CHECK CIRCUIT 608 (BK/YE) FOR AN OPEN
z
Disconnect: Instrument Cluster C220a.
z Measure the resistance between RCM C2041 pin 20, circuit 608
(BK/YE), harness side and instrument cluster C220a pin 12, circuit
608 (BK/YE), harness side. Yes
REPAIR the
circuit. GO to
N6 .
No
REPAIR the
instrument cluster.
GO to N6 . Klj . 39 ba
462003 Mustang Workshop Manual
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Pinpoint Test O: DTC B1870 —
Air Bag Indicator Shorted to Battery
Normal Operation
The air bag indicator is designed to illuminate for 6 (+/- 2) seconds when the ignition switch is turned to
the RUN position. This initial 6 seconds of illumination is considered normal operation and is called
proveout of the air bag indicator. The air bag indicator is then used to warn the driver that there is a
fault in the air bag supplemental restraint system (SRS).
While the air bag indicator is lit, the restraints control module (RCM) monitors the air bag indicator for
short to battery conditions. If the RCM detects a short to battery condition on the air bag indicator z
Is the resistance greater than 10 ohms? N5 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step N1.
z Was the continuous DTC retrieved during Step N1 an
intermittent fault? Yes
CHECK for causes
of intermittent
short to ground or
open on circuit 608
(BK/YE). Attempt
to recreate the
hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
N6 .
No
GO to N6 .
N6 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step N1.
z Were any continuous DTCs retrieved during Step N1? 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 . 40 ba
462003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

circuit, it will store a diagnostic trouble code (DTC) B1870 in memory.
If the RCM detects an air bag indicator failure in addition to another SRS failure, the RCM will send a
signal to the generic electronic module (GEM) to produce five sets of five tone bursts.
Possible Causes
An air bag indicator short to battery condition can be caused by:
zdamaged wiring on circuit 608 (BK/YE).
z an instrument cluster malfunction.
z an RCM internal concern.
PINPOINT TEST O: DTC B1870 — AIR BAG INDICATOR SHORTED
TO BATTERY Test Step Result / Action to
Take O1 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 B1870 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
O2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
O4 .
O2 CHECK THE AIR BAG INDICATOR CIRCUIT
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 Yes
INSTALL a new
RCM. GO to
O5 .
No
GO to O3 . Klj . 41 ba
462003 Mustang Workshop Manual
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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.
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 Key in ON position.
z Is the air bag indicator illuminated? O3 CHECK AIR BAG INDICATOR CIRCUIT FOR SHORT TO BATTERY
z
Key in OFF position.
z Disconnect: RCM C2041.
z Disconnect: Instrument Cluster C220a.
z Key in ON position.
z Measure the voltage between RCM C2041 pin 20, circuit 608
(BK/YE), harness side and ground.
z Is the voltage less than 0.2 volt? Yes
REPAIR the
instrument cluster.
GO to
O5 .
No
REPAIR the
circuit. GO to O5 .
O4 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step O1.
z Was the continuous DTC retrieved during Step O1 an
intermittent fault? Yes
CHECK for causes
of intermittent
short to battery on
circuit 608
(BK/YE). Attempt
to recreate the
hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent
concerns found.
GO to
O5 .
No
GO to O5 .
O5 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step O1.
z Were any continuous DTCs retrieved during Step O1? Yes
Do not clear any
DTCs until all
DTCs have been Klj . 42 ba
462003 Mustang Workshop Manual
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Pinpoint Test P: No Communication With The Restraints Control Module
Normal Operation
The RCM communicates with the scan tool using ISO 9141 communication mode through the data link
connector (DLC).
Possible Causes
A no communication condition can be caused by:
zdamage to circuit 70 (LB/WH).
z a damaged DLC.
z a damaged scan tool.
z an RCM internal concern.
PINPOINT TEST P: NO COMMUNICATION WITH THE RESTRAINTS
CONTROL MODULE 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 P1 CHECK THE RCM CONNECTOR C2041 AND CONNECTOR PIN 5
FOR DAMAGE 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 Yes
GO to
P2 .
No
REPAIR RCM
C2041 or RCM
C2041 pin 5 as
necessary. Klj . 43 ba
462003 Mustang Workshop Manual
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