display FORD MUSTANG 2003 Owner's Guide

DIAGNOSIS AND TESTING
Diagnostic Instructions —
Air Bag Supplemental Restraint
System (SRS)
The symptom chart can be used to help locate the air bag supplemental restraint system (SRS)
concerns if no diagnostic trouble codes (DTCs) are retrieved and the listed symptoms are observed.
Whether or not the listed symptoms are observed, always perform the following.
1. Retrieve all DTCs stored in the restraints control module (RCM) memory. Refer to Retrieve/Clear Continuous DTCs in this section.
2. Run the On- Demand Self Test to determine what DTCs are currently being sensed by the
restraints control module (RCM) (14B321). Refer to On- Demand Self Test in this section.
3. If the stored DTCs are different than the current DTCs, always repair the current DTCs first.
4. If memory displays different continuous DTCs than the On- Demand Self-Test, perform in the
following order:
z On- Demand Self- Test.
z Memory (Retrieve/Clear Continuous DTCs).
A DTC can indicate several concerns. The DTCs are to assist in system diagnosis and are not to be
considered definitive. Always refer to the pinpoint test corresponding to the DTC to determine where
the concern lies and to repair the concern correctly.
The SRS diagnostics can be divided into three sections.
zDiagnostic test modes
z PID/data monitor and record
z Active command modes
Diagnostic Test Modes
Two menu options are available under the diagnostic test modes.
zRetrieve/Clear Continuous DTCs.
z On- Demand Self Test.
SECTION 501-
20B: Supplemental Restraint System 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent scan
tool Klj . 1 ba
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Retrieve/Clear Continuous DTCs
During vehicle operation, the restraints control module (RCM) will detect and store both intermittent
and hard fault DTCs in nonvolatile memory. The DTC strategy employed by the RCM incorporates a
time-out scheme for determining when a concern exists in the system. This requires a concern to exist
for up to one minute in the system before the RCM will detect it. For the RCM to determine that a
concern no longer exists, the concern must be absent for up to one minute. The actual detection time-
outs vary with each DTC. The DTCs can be retrieved with a scan tool. Any DTCs stored in the RCM
will be displayed on the scan tool along with a brief description of the DTC. If no DTCs are present, the
scan tool will display a SYSTEM PASSED message. This option can also be used to clear DTCs from
the RCM memory, as long as the concern no longer exists. Once 128 key cycles have been recorded
since the concern was last detected, the DTC will automatically be removed from memory.
To retrieve or clear DTCs, follow these steps.
1. Connect the scan tool to the data link connector (DLC).
2. Turn the ignition switch to the RUN position.
3. Follow manufacturer's instructions for the scan tool being used.
4. All continuous DTCs will be displayed. Before proceeding with the clearing operation, make note of the DTCs displayed because, once cleared, they cannot be retrieved.
5. The scan tool will retrieve DTCs again after clearing DTCs and, if any remain, they will be displayed. Hard DTCs will be redisplayed after clearing DTCs since they cannot be cleared from
the RCM.
On- Demand Self Test
The On- Demand Self Test option is used to verify that no electrical concerns exist with the air bag
supplemental restraint system (SRS). Upon entering the self test, the restraints control module (RCM)
will make an electrical check of each electrical component in the system. If a concern is detected, a
DTC is displayed on the scan tool with a brief description of the DTC. Concerns detected during the
self test are not stored in memory, unless the same concern was also detected during normal vehicle
operation. The self test should always be run after any repair to verify that the repair was successful.
To run the On- Demand Self Test, follow these steps:
6. Connect a scan tool to the data link connector (DLC).
7. Turn the ignition switch to the RUN position.
8. Follow manufacturer's instructions for the scan tool being used.
9. The RCM will run the On- Demand Self Test and display on- demand DTCs (reflecting hard
system concerns) on the screen.
PID/Data Monitor and Record
The PID/Data Monitor and Record option allows the scan tool operator to read the state of several
parameter IDs (PIDs) to aid in diagnosing the system. PIDs are real time measurements of parameters
such as voltages, resistances, etc., calculated by the restraints control module (RCM) and sent to the
scan tool for display. Many of the PIDs supported by the RCM are calculated periodically and are,
therefore, not true real time readings.
To retrieve PIDs, follow these steps: 1. Connect the scan tool to data link connector (DLC). Klj . 2 ba
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2. Turn the ignition switch to the RUN position.
3. Follow manufacturer's instructions for the scan tool being used.
4. PIDs are continuously updated on the display.
Active Commands
This command allows the technician to verify operation of the air bag indicator and chime. When the
air bag output command is executed, the indicator and the chime are activated simultaneously for
approximately four seconds. Both devices are deactivated automatically.
Restraints Control Module (RCM) Diagnostic Trouble Code (DTC) Priority Table DTC
a LFC
b LFC
Priority Description Action To
Take — — 1 The Air Bag Indicator is Illuminated Continuously —
RCM
Disconnected, Inoperative, or Lost/Low Ignition Feed Go To Pinpoint
Test A .
B1342 24 2 RCM Is Faulted INSTALL a
new RCM.
B1231 19 3 RCM Crash Data Memory Full INSTALL a
new RCM.
B1921 21 4 RCM Bracket Ground Resistance High Go To Pinpoint
Test B .
C1414 29 5 Incorrect Vehicle Identification Code Go To Pinpoint
Test C .
B1887 15 6 Driver Air Bag Circuit Shorted to Ground Go To Pinpoint
Test D .
B1916 15 7 Driver Air Bag Circuit Shorted to Battery or Ignition Go To Pinpoint
Test E .
B1888 16 8 Passenger Air Bag Circuit Shorted to Ground Go To Pinpoint
Test F .
B1925 16 9 Passenger Air Bag Circuit Shorted to Battery or Ignition Go To Pinpoint
Test G .
B1932 32 10 Driver Air Bag Circuit Resistance High Go To Pinpoint
Test H .
B1933 33 11 Passenger Air Bag Circuit Resistance High Go To Pinpoint
Test I .
B1934 34 12 Driver Air Bag Circuit Resistance Low Go To Pinpoint
Test J .
B1935 35 13 Passenger Air Bag Circuit Resistance Low Go To Pinpoint
Test K .
B1892 — 17 Air Bag Tone Warning Indicator Circuit Shorted to
Ground or Open Go To Pinpoint
Test L .
B1891 — 18 Air Bag Tone Warning Indicator Circuit Shorted to Battery
or Ignition Go To Pinpoint
Test M .
B1869 Tone
c 19 Air Bag Indicator Inoperative Go To Pinpoint
Test N .
B1870 Tone
c 20 Air Bag Indicator Shorted to Battery Go To Pinpoint
Test O . Klj . 3 ba
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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~ ...