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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 D: LFC 38/39 DTC B1085 >> D14-D26

D14-D26




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

Pinpoint Tests

Pinpoint Test D: LFC 38/39 DTC B1085

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 the safety belt retractor adaptive load limiting circuits for the following faults:

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

If a fault is detected, the RCM will set and store DTC B1085 in memory and send a message to the Instrument Cluster (IC) module to flash a Lamp Fault Code (LFC) 38 or 39 on the air bag warning indicator. After the LFC(s) are displayed, the air bag warning indicator will remain illuminated for the rest of the ignition cycle.

The RCM monitors the safety belt adaptive load limiting retractor circuits for resistance and expects a normal resistance between 1.50 and 3.04 ohms.

If resistance 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 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 B1085. Fault PIDs that end in CM indicate continuous memory status and are associated with continuous DTC B1085.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Adaptive load limiting retractor
- RCM



PINPOINT TEST D: LFC 38/39 DTC B1085

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 safety belt buckle/retractor pretensioners or adaptive load limiting retractors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors, 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: SRScomponents 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 theSRS.

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D14 CHECK FOR A SHORT BETWEEN PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR CIRCUITS


- 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 passenger safety belt retractor C389-1, circuit CR147 (GN/OG), harness side and C389-2, circuit RR147 (YE/VT), harness side.




- Is the resistance greater than 10,000 ohms?

Yes
GO to D21.

No
REPAIR circuits CR147 (GN/OG) and RR147 (YE/VT). GO to D26.

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D15 CHECK THE PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR 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.
- Disconnect: Passenger safety belt Retractor C389.
- Connect a fused jumper wire between passenger safety belt retractor C389-1, circuit CR147 (GN/OG), harness side and C389-2, circuit RR147 (YE/VT), 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 .
- 1085_24_OD
- 1085_25_OD
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the passenger safety belt retractor circuits shorted together, a low resistance fault would normally be retrieved.
- Did the on-demand fault PIDs change from indicating an open circuit to a low resistance fault?

Yes
GO to D20.

No
GO to D16.

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D16 CHECK THE PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR 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 passenger safety belt retractor C389.
- Disconnect: RCM C310a and C310b.
- Measure resistance between RCM C310b, and passenger safety belt retractor C389, harness side using the following chart.









- Are the resistances less than 0.5 ohm?

Yes
GO to D21.

No
REPAIR the affected circuit. GO to D26.

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D17 CHECK THE PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR 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.
- Disconnect: Passenger Safety Belt Retractor C389.
- 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 .
- 1085_25_OD
- 1085_27_OD
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the passenger safety belt load limiting retractor disconnected, an open circuit fault would normally be retrieved.
- Did the on-demand fault PIDs change from indicating a short to ground to an open circuit fault?

Yes
GO to D20.

No
GO to D18.

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D18 CHECK THE PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR 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 passenger safety belt retractor:
- C389-1, circuit CR147 (GN/OG), harness side and ground.
- C389-2, circuit RR147 (YE/VT), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to D21.

No
REPAIR the affected circuit. GO to D26.

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D19 CHECK THE PASSENGER SAFETY BELT LOAD LIMITING RETRACTOR 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 Safety Belt Retractor C389.
- 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 passenger safety belt retractor:
- C389-2, circuit RR147 (YE/VT), harness side and ground.
- C389-1, circuit CR147 (GN/OG), harness side and ground.




- Is voltage present on either circuit?

Yes
REPAIR the affected circuit. GO to D26.

No
GO to D21.

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D20 CONFIRM THE SAFETY BELT RETRACTOR FAULT


NOTE: Make sure all restraint system components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out the self test. If not, DTCs will be recorded.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Prior to reconnecting any previously disconnected SRS component:
- inspect connector(s) (including any in-line connectors) for pushed out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- repair any concerns found. Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

- Connect: Affected Load Limiting Retractor C354 (Driver) C389 (Passenger).
- 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 All 1085 Fault PIDs.
- Refer to PID list in Normal Operation to view 1085 fault PIDs.
- Does the original on-demand 1085 fault PID indicate a fault?

Yes
INSTALL a new driver or passenger load limiting retractor. GO to D26.

No
In the process of diagnosing the fault, the fault condition has become intermittent. Using the fault PIDs recorded, GO to the appropriate pinpoint test.

For 1085_28_CM, 1085_29_CM, 1085_24_CM or 1085_25_CM, GO to D22.

For 1085_31_CM or 1085_27_CM, GO to D24.

For 1085_30_CM or 1085_26_CM, GO to D25.

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D21 CONFIRM THE RCM FAULT


NOTE: Make sure all restraint system components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out the self test. If not, DTCs will be recorded.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Prior to reconnecting any previously disconnected SRS component:
- inspect connector(s) (including any in-line connectors) for pushed out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- repair any concerns found. Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

- Connect: All Restraint System Components (if previously disconnected).
- Connect: RCM C310a and C310b (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.
- 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 1085 Fault PIDs.
- Refer to PID list in Normal Operation to view 1085 fault PIDs.
- Does the original on-demand 1085 fault PID indicate a fault?

Yes
INSTALL a new RCM and CARRY OUT Programmable Module Installation (PMI). REFER to Restraints Control Module (RCM) Service and Repair. GO to D26. Programming and Relearning

No
In the process of diagnosing the fault, the fault condition has become intermittent. 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.

For 1085_28_CM, 1085_29_CM, 1085_24_CM or 1085_25_CM, GO to D22.

For 1085_31_CM or 1085_27_CM , GO to D24.

For 1085_30_CM or 1085_26_CM, GO to D25.

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D22 CHECK THE SAFETY BELT LOAD LIMITING RETRACTOR FAULT PIDs FOR AN INTERMITTENT LOW RESISTANCE OR OPEN CIRCUIT


- If the fault PID or was reported for the driver safety belt load limiting retractor, monitor the following on the scan tool.
- D_LOAD PID.
- 1085_28_OD and 1085_29_OD) on-demand fault PIDs.
- If the fault PID was reported for the passenger safety belt load load limiting retractor, monitor the following on the scan tool.
- P_LOAD PID.
- 1085_24_OD and 1085_25_OD on-demand fault PID.
- NOTE: A resistance PID that reads between 1.36 and 1.50 ohms or between 3.04 and 3.72 ohms may or may not set an on-demand DTC, yet indicates a strong potential of a fault to occur. Make sure to thoroughly check wire harness(es), connectors and terminals as they are the likely source of the fault condition.
- Attempt to recreate the fault by wiggling the connectors (including any in-line connectors) and flexing the wire harness.
- Does any on-demand 1085 fault PID indicate a fault is present or is the PID value less than 1.50 ohms or greater than 3.04 ohms?

Yes
DEPOWER the SRS and REPAIR as necessary.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to D26.

No
GO to D23.

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D23 CHECK THE HARNESS AND CONNECTORS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect the affected load limiting retractor C354 (driver) or C389 (passenger):
- inspect connector(s) (including any in-line connectors) for corrosion, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- Were any concerns found?

Yes
REPAIR as necessary.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to D26.

No
The fault is not present and cannot be recreated at this time. GO to D26.

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D24 CHECK THE SAFETY BELT LOAD LIMITING RETRACTOR FAULT PIDs FOR AN INTERMITTENT SHORT TO GROUND


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM.
- If the fault PID was reported for the driver safety belt load limiting retractor, monitor 1085_31_OD on-demand fault PID.
- If the fault PID was reported for the passenger safety belt load limiting retractor, monitor 1085_27_OD on-demand fault PID.
- Attempt to recreate the fault by wiggling connectors (including any in-line connectors) and flexing the wire harness.
- Does any on-demand 1085 fault PID indicate a fault is present?

Yes
DEPOWER the SRS and REPAIR as necessary.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to D26.

No
The fault is not present and cannot be recreated at this time. GO to D26.

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D25 CHECK THE SAFETY BELT LOAD LIMITING RETRACTOR FAULT PIDs FOR AN INTERMITTENT SHORT TO VOLTAGE


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM.
- If the fault PID was reported for the driver safety belt load limiting retractor, monitor the 1085_30_OD on-demand fault PID.
- If the fault PID was reported for the passenger safety belt load limiting retractor, monitor the 1085_26_OD on-demand fault PID.
- Attempt to recreate the fault by wiggling the connectors (including any in-line connectors) and flexing the wire harness.
- Does any on-demand 1085 fault PID indicate a fault is present?

Yes
DEPOWER the SRS and REPAIR as necessary.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to D26.

No
The fault is not present and cannot be recreated at this time. GO to D26.

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D26 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 - Restraints.
- NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM and OCSM.
- Are any RCM and/or OCSM DTCs retrieved on-demand during self-test?

Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the DTC Charts for pinpoint test direction. [1][2]Diagnostic Trouble Code Descriptions

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

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