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Home >> Ford >> 2009 >> Mustang V6-4.0L >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test K: LFC 19 And 21/DTC B2293 >> K21-K39

K21-K39




Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)

Pinpoint Tests

Pinpoint Test K: LFC 19 and 21/DTC B2293

Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number

Normal Operation

The front air bags will deploy upon receiving a flow of current from the Restraints Control Module (RCM).

The Restraints Control Module (RCM) continuously checks all of the front air bag circuits. If the RCM detects one of the following faults on any of the front air bag circuits, it will store DTC B2293 in memory and flash either Lamp Fault Code (LFC) 19 or 21 depending on the fault on the air bag warning indicator.





a Fault PIDs that end in OD indicate an on-demand status and are associated with on-demand DTC B2293. Fault PIDs that end in CM indicate continuous memory status and are associated with continuous DTC B2293.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Driver/passenger air bag module
- RCM

PINPOINT TEST K: LFC 19 AND 21/DTC B2293

WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.

WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when making measurements. Failure to use the correct probe adapter(s) may damage the connector. Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Inspection and Verification

NOTE: Supplemental Restraint System (SRS) components should only be disconnected or reconnected when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

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K21 CHECK DRIVER AIR BAG MODULE LOOP 2 CIRCUITS FOR A SHORT TO GROUND


- Disconnect: Clockspring C2274.
- Measure the resistance between clockspring:
- C2274-8, circuit 1516 (YE/WH), harness side and ground.
- C2274-9, circuit 1517 (RD/OG), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
INSTALL a new clockspring. REFER to Clockspring Service and Repair. GO to K39.

No
Due to the shorting bar feature in the electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit 1516 (YE/WH) or 1517 (RD/OG). GO to K39.

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K22 CHECK DRIVER AIR BAG MODULE LOOP 2 CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Air Bag Module Loop 2 Restraint System Diagnostic Tool.
- Disconnect: RCM C2041a and C2041b.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure the voltage between driver air bag module:
- loop 2 electrical connector, circuit 1516 (YE/WH), harness side and ground.
- loop 2 electrical connector, circuit 1517 (RD/OG), harness side and ground.




- Is voltage present on either circuit?

Yes
GO to K23.

No
GO to K37.

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K23 CHECK DRIVER AIR BAG MODULE LOOP 2 CIRCUITS FOR A SHORT TO VOLTAGE BETWEEN THE RCM AND CLOCKSPRING


- Ignition OFF.
- Disconnect: Clockspring C2274.
- Ignition ON.
- Measure the voltage between clockspring connector:
- C2274-8, circuit 1516 (YE/WH), harness side and ground.
- C2274-9, circuit 1517 (RD/OG), harness side and ground.




- Is voltage present on either circuit?

Yes
Due to the shorting bar feature in the electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit 1516 (YE/WH) or 1517 (RD/OG). GO to K39.

No
INSTALL a new clockspring. REFER to Clockspring Service and Repair. GO to K39.

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K24 CHECK FOR AN OPEN ON CIRCUIT 1516 (YE/WH) BETWEEN THE RCM AND DRIVER AIR BAG MODULE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Air Bag Module Loop 2 Restraint System Diagnostic Tool.
- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between RCM C2041a-5, circuit 1516 (YE/WH), harness side and driver air bag module loop 2, circuit 1516 (YE/WH), harness side.




- Is resistance less than 0.5 ohm?

Yes
GO to K26.

No
GO to K25.

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K25 CHECK FOR AN OPEN ON CIRCUIT 1516 (YE/WH) BETWEEN THE RCM AND CLOCKSPRING


- Disconnect: Clockspring C2274.
- Measure the resistance between RCM C2041a-5, circuit 1516 (YE/WH), harness side and clockspring C2274-8, circuit 1516 (YE/WH), harness side.




- Is resistance less than 0.5 ohm?

Yes
INSTALL a new clockspring. REFER to Clockspring Service and Repair. GO to K39.

No
REPAIR circuit 1516 (YE/WH). GO to K39.

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K26 CHECK FOR AN OPEN ON CIRCUIT 1517 (RD/OG) BETWEEN THE RCM AND DRIVER AIR BAG MODULE


- Measure the resistance between RCM C2041a-6, circuit 1517 (RD/OG), harness side and driver air bag module loop 2, circuit 1517 (RD/OG), harness side.




- Is resistance less than 0.5 ohm?

Yes
GO to K37.

No
GO to K27.

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K27 CHECK FOR AN OPEN ON CIRCUIT 1517 (RD/OG) BETWEEN THE RCM AND CLOCKSPRING


- Disconnect: Clockspring C2274.
- Measure the resistance between RCM C2041a-6, circuit 1517 (RD/OG), harness side and clockspring C2274-9, circuit 1517 (RD/OG), harness side.




- Is resistance less than 0.5 ohm?

Yes
INSTALL a new clockspring. REFER to Clockspring Service and Repair. GO to K39.

No
REPAIR circuit 1517 (RD/OG). GO to K39.

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K28 CHECK FOR A SHORT BETWEEN DRIVER AIR BAG MODULE LOOP 2 CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Air Bag Module Loop 2 Restraint System Diagnostic Tool.
- Measure the resistance between driver air bag module loop 2 electrical connector, circuit 1516 (YE/WH), harness side, and circuit 1517 (RD/OG), harness side.




- Is resistance greater than 10,000 ohms?

Yes
GO to K37.

No
GO to K29.

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K29 CHECK THE RCM FOR LOW RESISTANCE


- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between RCM C2041a pin 5, component side and pin 6, component side.




- Is resistance greater than 10,000 ohms?

Yes
GO to K30.

No
GO to K37.

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K30 CHECK FOR A SHORT BETWEEN DRIVER AIR BAG MODULE LOOP 2 CIRCUITS


- Connect: RCM C2041a and C2041b.
- Disconnect: Clockspring C2274.
- Measure the resistance between clockspring C2274-8, circuit 1516 (YE/WH), harness side and C2274-9, circuit 1517 (RD/OG), harness side.




- Is resistance greater than 10,000 ohms?

Yes
INSTALL a new clockspring. REFER to Clockspring Service and Repair. GO to K39.

No
REPAIR circuits 1516 (YE/WH) and 1517 (RD/OG). GO to K39.

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K31 CHECK PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS FOR A SHORT TO GROUND


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between passenger air bag module:
- C256-1, circuit 1518 (RD/WH), harness side and ground.
- C256-2, circuit 1519 (LG/RD), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to K37.

No
Due to the shorting bar feature in the electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit 1518 (RD/WH) or 1519 (LG/RD). GO to K39.

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K32 CHECK PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
- Disconnect: RCM C2041a and C2041b.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure the voltage between passenger air bag module:
- C256-1, circuit 1518 (RD/WH), harness side and ground.
- C256-2, circuit 1519 (LG/RD), harness side and ground.




- Is voltage present on either circuit?

Yes
Due to the shorting bar feature in the electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit 1518 (RD/WH) or 1519 (LG/RD). GO to K39.

No
GO to K37.

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K33 CHECK FOR AN OPEN ON CIRCUIT 1518 (RD/WH) BETWEEN THE RCM AND PASSENGER AIR BAG MODULE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between RCM C2041a-13, circuit 1518 (RD/WH), harness side and passenger air bag module C256-1, circuit 1518 (RD/WH), harness side.




- Is resistance less than 0.5 ohm?

Yes
GO to K34.

No
REPAIR circuit 1518 (RD/WH). GO to K39.

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K34 CHECK FOR AN OPEN ON CIRCUIT 1519 (LG/RD) BETWEEN THE RCM AND PASSENGER AIR BAG MODULE


- Measure the resistance between RCM C2041a-14, circuit 1519 (LG/RD), harness side and passenger air bag module C256-2, circuit 1519 (LG/RD), harness side.




- Is resistance less than 0.5 ohm?

Yes
GO to K37.

No
REPAIR circuit 1519 (LG/RD). GO to K39.

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K35 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module Restraint System Diagnostic Tool.
- Measure the resistance between passenger air bag module C256-1, circuit 1518 (RD/WH), harness side and C256-2, circuit 1519 (LG/RD), harness side.




- Is resistance greater than 10,000 ohms?

Yes
GO to K37.

No
GO to K36.

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K36 CHECK THE RCM FOR LOW RESISTANCE


- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between RCM C2041a pin 13, component side and pin 14, component side.




- Is resistance greater than 10,000 ohms?

Yes
REPAIR circuits 1518 (RD/WH) and 1519 (LG/RD). GO to K39.

No
GO to K37.

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K37 CONFIRM THE RCM FAULT


NOTE: Make sure all restraint system diagnostic tools, sensor electrical connectors and the RCM electrical connector are connected before carrying out the on-demand self test. If not, erroneous DTCs will be recorded.

- Ignition OFF.
- Connect: Driver or Passenger Air Bag Module Restraint System Diagnostic Tool(s).
- Connect: RCM C2041a and C2041b.
- Connect: Clockspring C2274 (if previously disconnected).
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record All 2293 Fault PIDs .
- Refer to PID list in Normal Operation to view B2293 fault PIDs.
- Does the original on-demand DTC B2293 fault PID indicate a fault?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to K39.

No
Fault corrected. GO to K39.

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K38 CHECK FOR AN INTERMITTENT FAULT


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- If the fault PID was reported for the driver air bag module:
- remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- connect restraint system diagnostic tools 418-F395 (2 required) to driver air bag module loop 1 and loop 2 connectors.
- If the fault PID was reported for the passenger air bag module:
- disconnect passenger air bag module C256.
- connect Restraint System Diagnostic Tool 418-F403 to passenger air bag module C256.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record All 2293 Fault PIDs .
- Refer to PID list in Normal Operation to view B2293 fault PIDs.
- Do any on-demand DTC B2293 fault PIDs indicate a fault?

Yes
This is a hard fault. The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test.

CHECK for causes of the intermittent fault at or near the affected air bag module connector. REPAIR any intermittent concerns found.

If an intermittent concern was found and repaired, GO to K39.

If an intermittent concern was not found, use the fault PIDs recorded and GO to the appropriate pinpoint test step.

For 2293_31_OD (Air Bag Circuit Short to Ground - Loop No. 1, Front Driver Side), GO to K3.

For 2293_30_OD (Air Bag Circuit Short to Battery - Loop No. 1, Front Driver Side), GO to K5.

For 2293_29_OD (Air Bag Circuit Open - Loop No. 1, Front Driver Side), GO to K7.

For 2293_28_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 1, Front Driver Side), GO to K11.

For 2293_27_OD (Air Bag Circuit Short to Ground - Loop No. 1, Front Passenger Side), GO to K14.

For 2293_26_OD (Air Bag Circuit Short to Battery - Loop No. 1, Front Passenger Side), GO to K15.

For 2293_25_OD (Air Bag Circuit Open - Loop No. 1, Front Passenger Side), GO to K16.

For 2293_24_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 1, Front Passenger Side), GO to K18.

For 2293_23_OD (Air Bag Circuit Short to Ground - Loop No. 2, Front Driver Side), GO to K20.

For 2293_22_OD (Air Bag Circuit Short to Battery - Loop No. 2, Front Driver Side), GO to K22.

For 2293_21_OD (Air Bag Circuit Open - Loop No. 2, Front Driver Side), GO to K24.

For 2293_20_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 2, Front Driver Side), GO to K28.

For 2293_19_OD (Air Bag Circuit Short to Ground - Loop No. 2, Front Passenger Side), GO to K31.

For 2293_18_OD (Air Bag Circuit Short to Battery - Loop No. 2, Front Passenger Side), GO to K32.

For 2293_17_OD (Air Bag Circuit Open - Loop No. 2, Front Passenger Side), GO to K33.

For 2293_16_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 2, Front Passenger Side), GO to K35.

No
CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness, cycling the ignition frequently and rotating the steering wheel (driver air bag module fault). Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. REPAIR any intermittent wiring, terminal or connector concerns found. GO to K39.

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K39 CHECK FOR ADDITIONAL SRS DTCs


- Ignition OFF.
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Reconnect all SRS components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Are any RCM DTCs retrieved on-demand during the self test?

Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the DTC Chart for pinpoint test direction. Diagnostic Trouble Code Tests and Associated Procedures

No
CLEAR all RCM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

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