AC system FORD MUSTANG 2003 Workshop Manual

z
a poor connection or corrosion in the passenger air bag module circuits.
z an open circuit or high resistance in the wiring harness.
z an open circuit or high resistance in the passenger air bag module.
z an RCM internal concern.
PINPOINT TEST I: LFC 33/DTC B1933 — PASSENGER AIR BAG
CIRCUIT RESISTANCE HIGH Test Step Result / Action to
Take I1 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 B1933 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 I2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to I4 .
I2 CHECK THE PASSENGER 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
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 Yes
GO to
I3 .
No
INSTALL a new
passenger air bag
module. GO to I5 . Klj . 24 ba
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System (SRS) in the Diagnosis and Testing portion of this section.
z Key in OFF position.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1933 retrieved? I3 CHECK THE PASSENGER AIR BAG MODULE CIRCUIT
z
Key in OFF position.
z Disconnect: RCM C2041.
z Disconnect: Passenger Air Bag Restraint System Diagnostic Tool.
z NOTE: By disconnecting the RCM connector, circuit 607 (LB/OG)
and circuit 616 (PK/BK) of the RCM connector are shorted together
with a shorting bar. Do not remove the shorting bar.
z NOTE: Zero the multimeter prior to taking the measurement.
z Measure the resistance between passenger air bag C256, circuit 607
(LB/OG), harness side and passenger air bag C256, circuit 616
(PK/BK), harness side.
z Is the resistance greater than 0.5 ohm? Yes
REPAIR the circuit
(s) as necessary.
GO to
I5 .
No
INSTALL a new
RCM. GO to I5 .
I4 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step I1.
z Was the continuous DTC retrieved during Step I1 an intermittent
fault? Yes
CHECK for causes
of intermittent high
resistance on
circuit 607 (LB/OG)
and circuit 616
(PK/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
I5 .
No
GO to I5 .
I5 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step I1.
z Were any continuous DTCs retrieved during Step I1? Yes
Do not clear any
DTCs until all
DTCs have been
resolved. GO to
the Restraints
Control Module
(RCM) Diagnostic Klj . 25 ba
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Pinpoint Test J: LFC 34/DTC B1934 —
Driver Air Bag Circuit Resistance Low
Normal Operation
The restraints control module (RCM) monitors the resistance of the driver air bag ignitor by measuring
the resistance between pins 3 and 4. If the RCM detects low resistance between these pins, it will
store a diagnostic trouble code (DTC) B1934 in memory and flash a lamp fault code (LFC) 34 (or
higher priority code if one exists) on the air bag indicator.
Possible Causes
Driver air bag low resistance can be caused by:
za short in the clockspring windings.
z a short in the wiring harness.
z a low resistance in the driver air bag module.
z an RCM internal concern.
z worn or damaged short bar or camming beam.
PINPOINT TEST J: LFC 34/DTC B1934 — DRIVER AIR BAG CIRCUIT
RESISTANCE LOW 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 J1 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. 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 Klj . 26 ba
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z
Was DTC B1934 retrieved during the on- demand self test? on-
demand self
test. GO to J2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to J5 .
J2 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
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 Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1934 retrieved? Yes
GO to
J3 .
No
INSTALL a new
driver air bag
module. GO to J6 .
J3 CHECK THE DRIVER AIR BAG MODULE CIRCUIT
z
Key in OFF position.
z Disconnect: Driver Air Bag Restraint System Diagnostic Tool.
z Measure the resistance between driver air bag C216, circuit 614
(GY/OG), harness side and between driver air bag C216, circuit 615
(GY/WH), harness side.
z Is the resistance greater than 10,000 ohms? Yes
INSTALL a new
RCM. GO to
J6 .
No
GO to J4 .
J4 CHECK THE CLOCKSPRING Klj . 27 ba
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z
Disconnect: Clockspring C218b.
z Measure the resistance between clockspring C218b, circuit 614
(GY/OG) and circuit 615 (GY/WH), harness side.
z Is the resistance greater than 10,000 ohms? Yes
INSTALL a new
clockspring. GO to
J6
.
No
REPAIR the circuit
(s) as necessary.
GO to J6 .
J5 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step J1.
z Was the continuous DTC retrieved during Step J1 an
intermittent fault? Yes
CHECK for causes
of intermittent low
resistance 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
J6 .
No
GO to J6 .
J6 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step J1.
z Were any continuous DTCs retrieved during Step J1? 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 Klj . 28 ba
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Pinpoint Test K: LFC 35/DTC B1935 —
Passenger Air Bag Circuit Resistance Low
Normal Operation
The restraints control module (RCM) monitors the resistance of the passenger air bag ignitor by
measuring the resistance between pins 6 and 7. If the RCM detects low resistance between these
pins, it will store a diagnostic trouble code (DTC) B1935 in memory and flash a lamp fault code (LFC)
35 (or higher priority code if one exists) on the air bag indicator.
Possible Causes
Passenger air bag low resistance can be caused by:
za short in the wiring harness.
z a low resistance in the passenger air bag module.
z an RCM internal concern.
z a worn or damaged connector shorting bar or camming beam.
PINPOINT TEST K: LFC 35/DTC B1935 — PASSENGER AIR BAG
CIRCUIT RESISTANCE LOW (SRS) in this
section. CLEAR all
DTCs. Test Step Result / Action to
Take K1 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 B1935 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 K2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
K4 .
K2 CHECK THE PASSENGER 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. Yes
GO to
K3 .
No
INSTALL a new Klj . 29 ba
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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 Key in ON position.
z Enter the following diagnostic mode on the diagnostic tool: On-
Demand Self Test.
z Was DTC B1935 retrieved? passenger air bag
module. GO to
K5 .
K3 CHECK THE PASSENGER AIR BAG MODULE CIRCUIT
z
Key in OFF position.
z Disconnect: Passenger Air Bag Restraint System Diagnostic Tool.
z Measure the resistance between passenger air bag C256, circuit 607
(LB/OG), harness side and passenger air bag C256, circuit 616
(PK/BK), harness side.
z Is the resistance greater than 10,000 ohm? Yes
INSTALL a new
RCM. GO to
K5 .
No
REPAIR the circuit
(s) as necessary.
GO to K5 .
K4 CHECK FOR AN INTERMITTENT FAULT
z
Refer to the continuous DTCs recorded during Step K1.
z Was the continuous DTC retrieved during Step K1 an
intermittent fault? Yes
CHECK for causes
of intermittent low
resistance on
circuit 607 (LB/OG)
and circuit 616
(PK/BK). Attempt
to recreate the
hard fault by
flexing the wire
harness and
cycling the ignition
key frequently.
REPAIR any
intermittent Klj . 30 ba
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Pinpoint Test L: B1892 —
Air Bag Tone Warning Indicator Circuit Shorted to Ground or Open
Normal Operation
The restraints control module (RCM) monitors its connection to the generic electronic module (GEM) at
C201e 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 ground or open on the connection to the GEM,
it will store a diagnostic trouble code (DTC) B1892 in memory.
Possible Causes
An air bag tone warning indicator circuit short to ground or open can be caused by:
za short to ground or open on circuit 1083 (LB/BK).
z a damaged or inoperative GEM.
PINPOINT TEST L: DTC B1892 — AIR BAG TONE WARNING
INDICATOR CIRCUIT SHORTED TO GROUND OR OPEN concerns found.
GO to
K5 .
No
GO to K5 .
K5 CHECK FOR ADDITIONAL DTCs
z
Refer to the continuous DTCs recorded during Step K1.
z Were any continuous DTCs retrieved during Step K1? 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 L1 CHECK FOR A HARD OR INTERMITTENT DTC Klj . 31 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 B1892 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
L2 .
No
This is an
intermittent fault.
The fault condition
is not present at
this time. GO to
L5 .
L2 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.
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 Measure the resistance between RCM C2041 pin 26, circuit 1083
(LB/BK), harness side and RCM C2041 pin 21, circuit 397 (BK/WH),
harness side. Yes
REPAIR the
circuit. GO to
L6 .
No
GO to L3 . Klj . 32 ba
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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
462003 Mustang Workshop Manual
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