Operation CHARM: Car repair manuals for everyone.
Home >> Lincoln >> 2009 >> MKS FWD V6-3.7L >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test L: LFC 19/21 DTC B2293 >> L1-L19

L1-L19




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

Pinpoint Tests

Pinpoint Test L: LFC 19/21 DTC B2293

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

Normal Operation

The Restraints Control Module (RCM) continuously monitors all front air bag module circuits (loop) for the following faults:

- Resistance out of range
- Unexpected voltage
- Short to ground

If a fault is detected, the RCM will store DTC B2293 in memory and send a message to the Instrument Cluster (IC) module to flash a Lamp Fault Code (LFC) 19 or 21 on the air bag warning indicator. After the LFCs are displayed, the air bag warning indicator will remain illuminated for the rest of the ignition cycle.

The RCM monitors all front air bag module circuits for resistance and expects a normal resistance for the driver air bag module loops between 1.84 and 3.96 ohms. The normal expected resistance for the passenger air bag module loops is between 1.50 and 3.04 ohms.

If a resistance for the driver air bag loops 1 or 2 is between 1.36 and 1.84 ohms or between 3.96 and 4.70 ohms, there exists a strong potential for a fault to occur (a DTC may or may not set). The RCM will also set a DTC if the loop resistance is less than 1.36 ohms or greater than 4.70 ohms.

If a loop resistance for the passenger air bag loops 1 and 2 is between 1.04 and 1.50 ohms or between 3.04 and 3.72 ohms, there exists a strong potential for a fault to occur (a DTC may or may not set). The RCM will also set a DTC if the loop resistance is less than 1.04 ohms or greater than 3.72 ohms.





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 air bag module
- Passenger air bag module
- RCM



PINPOINT TEST L: LFC 19/21 DTC B2293

WARNING: Do not handle, move or change the original horizontal mounting position of the restraints control module (RCM) while the RCM is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the Safety Canopy(R) and cause serious personal injury or death.

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: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

NOTE: 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.

-------------------------------------------------
L1 RETRIEVE RCM DTCs


- Ignition ON.
- 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 2293 fault PIDs.
- Do any on-demand 2293 fault PIDs indicate a fault?

Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self test.

Using the fault PIDs recorded, GO to the appropriate pinpoint test step.

For 2293_28_OD, GO to L2.

For 2293_29_OD, GO to L2.

For 2293_31_OD, GO to L10.

For 2293_30_OD, GO to L13.

For 2293_20_OD, GO to L15.

For 2293_21_OD, GO to L15.

For 2293_23_OD, GO to L23.

For 2293_22_OD, GO to L26.

For 2293_24_OD, GO to L28.

For 2293_25_OD, GO to L28.

For 2293_27_OD, GO to L34.

For 2293_26_OD, GO to L36.

For 2293_16_OD, GO to L37.

For 2293_17_OD, GO to L37.

For 2293_19_OD, GO to L43.

For 2293_18_OD, GO to L45.

No
This is an intermittent fault when present as a CMDTC only.

Using the fault PIDs recorded, GO to the appropriate pinpoint test step.

For 2293_28_CM or 2293_20_CM, GO to L50.

For 2293_29_CM or 2293_21_CM, GO to L50.

For 2293_31_CM or 2293_23_CM, GO to L51.

For 2293_30_CM or 2293_22_CM, GO to L53.

For 2293_24_CM or 2293_16_CM, GO to L50.

For 2293_25_CM or 2293_17_CM, GO to L50.

For 2293_27_CM or 2293_19_CM, GO to L52.

For 2293_26_CM or 2293_18_CM, GO to L54.

-------------------------------------------------
L2 CHECK THE DRIVER AIR BAG MODULE LOOP 1 RESISTANCE (D_ABAGR) PID


- Enter the following diagnostic mode on the scan tool: DataLogger - RCM .
- Enter the following diagnostic mode on the scan tool: D_ABAGR PID.
- Does the PID value read between 1.84 and 3.96 ohms?

Yes
GO to L49.

No
GO to L3.

-------------------------------------------------
L3 CHECK THE DRIVER AIR BAG MODULE LOOP 1 RESISTANCE (D_ABAGR) PID WHILE CARRYING OUT A HARNESS TEST


- NOTE: Do not remove the driver air bag module from its mounted position at this time.
- While monitoring the D_ABAGR PID carry out a harness test of the driver air bag circuits and accessible connectors (including any in-line connectors) by wiggling and flexing the wire harness, connectors, tilting and rotating the steering wheel frequently.
- Does the PID value read between 1.84 and 3.96 ohms while carrying out the harness test?

Yes
DEPOWER the SRS and REPAIR the connector, terminals or wire harness or INSTALL a new clockspring as needed. REFER to Clockspring Service and Repair.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to L56.

No
If the D_ABAGR PID is less than 1.84 ohms, GO to L4.

If the D_ABAGR PID is greater than 3.96 ohms, GO to L7.

-------------------------------------------------
L4 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- 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.
- 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 the Following Fault PIDs.
- 2293_28_OD
- 2293_29_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a low resistance to an open circuit fault?

Yes
GO to L46.

No
GO to L5.

-------------------------------------------------
L5 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED) (CLOCKSPRING DISCONNECTED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Disconnect: Clockspring C218.
- Ignition ON.
- 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 the Following Fault PIDs.
- 2293_28_OD
- 2293_29_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a low resistance to an open circuit fault?

Yes
GO to L48.

No
GO to L6.

-------------------------------------------------
L6 CHECK THE RCM FOR LOW RESISTANCE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a pins 3 and 4, component side.




- Is the resistance greater than 10,000 ohms?

Yes
REPAIR circuits CR101 (VT/BN) and RR101 (YE/GN). GO to L56.

No
GO to L49.

-------------------------------------------------
L7 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (OPEN INDICATED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- Connect a fused jumper wire between driver air bag module loop 1 electrical connector between pins 1 and 2, harness side.
- 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.
- 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 the Following Fault PIDs .
- 2293_28_OD
- 2293_29_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module loop 1 circuits shorted together, a low resistance fault would normally be retrieved on loop 1. Loop 2 will show an open circuit fault due to the driver air bag being disconnected.
- Did the on-demand fault PID change from an open circuit to a low resistance fault?

Yes
GO to L46.

No
GO to L8.

-------------------------------------------------
L8 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (OPEN INDICATED) (CLOCKSPRING DISCONNECTED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Remove the fused jumper wire from driver air bag module loop 1 electrical connector.
- Disconnect: Clockspring C218.
- Connect a fused jumper wire between clockspring C218-1, circuit CR101 (VT/BN), harness side and clockspring C218-9, circuit RR101 (YE/GN), harness side.
- Ignition ON.
- 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 the Following Fault PIDs .
- 2293_28_OD
- 2293_29_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module loop 1 circuits shorted together, a low resistance fault would normally be retrieved on loop 1. Loop 2 will show an open circuit fault due to the driver air bag being disconnected.
- Did the on-demand fault PIDs change from an open circuit to a low resistance fault?

Yes
GO to L48.

No
GO to L9.

-------------------------------------------------
L9 CHECK THE DRIVER AIR BAG MODULE LOOP 1 CIRCUITS FOR AN OPEN


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the fused jumper wire from the clockspring connector.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a, harness side and clockspring C218, harness side using the following chart.









- Are the resistances less than 0.5 ohm?

Yes
GO to L49.

No
REPAIR circuit CR101 (VT/BN) or RR101 (YE/GN). GO to L56.

-------------------------------------------------
L10 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- 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.
- 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 the Following Fault PIDs.
- 2293_29_OD
- 2293_31_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a short to ground to an open circuit fault?

Yes
GO to L46.

No
GO to L11.

-------------------------------------------------
L11 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED) (CLOCKSPRING DISCONNECTED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Disconnect: Clockspring C218.
- Ignition ON.
- 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 the Following Fault PIDs.
- 2293_29_OD
- 2293_31_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PID change from a short to ground to an open circuit fault?

Yes
GO to L48.

No
GO to L12.

-------------------------------------------------
L12 CHECK THE DRIVER AIR BAG MODULE LOOP 1 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: RCM C310a and C310b.
- Measure the resistance between clockspring:
- C218-1, circuit CR101 (VT/BN), harness side and ground.
- C218-9, circuit RR101 (YE/GN), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to L49.

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

REPAIR circuit CR101 (VT/BN) or RR101 (YE/GN). GO to L56.

-------------------------------------------------
L13 CHECK THE DRIVER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO BATTERY INDICATED) (CLOCKSPRING DISCONNECTED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- Disconnect: Clockspring C218.
- 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.
- 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 the Following Fault PIDs.
- 2293_29_OD
- 2293_30_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a short to battery to an open circuit fault?

Yes
GO to L48.

No
GO to L14.

-------------------------------------------------
L14 CHECK THE DRIVER AIR BAG MODULE LOOP 1 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: RCM C310a and C310b.
- 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 clockspring:
- C218-1, circuit CR101 (VT/BN), harness side and ground.
- C218-9, circuit RR101 (YE/GN), harness side and ground.




- Is voltage present on either circuit?

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

REPAIR circuit CR101 (VT/BN) or RR101 (YE/GN). GO to L56.

No
GO to L49.

-------------------------------------------------
L15 CHECK THE DRIVER AIR BAG MODULE LOOP 2 RESISTANCE (D_ABAGR2) PID


- Enter the following diagnostic mode on the scan tool: DataLogger - RCM .
- Enter the following diagnostic mode on the scan tool: D_ABAGR2 PID.
- Does the PID value read between 1.84 and 3.96 ohms?

Yes
GO to L49.

No
GO to L16.

-------------------------------------------------
L16 CHECK THE DRIVER AIR BAG MODULE LOOP 2 RESISTANCE (D_ABAGR2) PID WHILE CARRYING OUT A HARNESS TEST


- NOTE: Do not remove the driver air bag module from its mounted position at this time.
- While monitoring the D_ABAGR2 PID carry out a harness test of the driver air bag circuits and accessible connectors (including any in-line connectors), by wiggling and flexing the wire harness, connectors, tilting and rotating the steering wheel frequently.
- Does the PID value read between 1.84 and 3.96 ohms while carrying out the harness test?

Yes
DEPOWER the SRS and REPAIR the connector, terminals or wire harness or INSTALL a new clockspring as needed. REFER to Clockspring Service and Repair.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to L56.

No
If the D_ABAGR2 PID is less than 1.84 ohms, GO to L17.

If the D_ABAGR2 PID is greater than 3.96 ohms, GO to L20.

-------------------------------------------------
L17 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- 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.
- 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 the Following Fault PIDs .
- 2293_20_OD
- 2293_21_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a low resistance to an open circuit fault?

Yes
GO to L46.

No
GO to L18.

-------------------------------------------------
L18 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FOR FAULT PID FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED) (CLOCKSPRING DISCONNECTED)


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Disconnect: Clockspring C218.
- Ignition ON.
- 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 the Following Fault PIDs .
- 2293_20_OD
- 2293_21_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the on-demand fault PIDs change from a low resistance to an open circuit fault?

Yes
GO to L48.

No
GO to L19.

-------------------------------------------------
L19 CHECK THE RCM FOR LOW RESISTANCE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a pins 15 and 16, component side.




- Is the resistance greater than 10,000 ohms?

Yes
REPAIR circuits CR102 (BU) and RR102 (WH). GO to L56.

No
GO to L49.

-------------------------------------------------
pro multis · About Operation CHARM