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Home >> Mercury >> 2009 >> Sable FWD V6-3.5L >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test C: LFC 38/39 DTC B1085 >> C18-C26

C18-C26





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

Pinpoint Tests

Pinpoint Test C: 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 adaptive load limiting retractor circuits for an acceptable resistance range, unacceptable voltage and shorts to ground. The RCM will set and store on-demand DTC B1085 in memory if any of these conditions are detected to be outside of their respectful range. If the RCM detects a fault, it will 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.

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

If a safety belt adaptive load limiting retractor loop resistance is between 1.04 and 1.50 ohms or between 3.04 and 3.72 ohms, there exists a strong potential for an intermittent fault, a DTC may or may not set. The RCM will also set an on-demand 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 B1085. Fault PIDs that end in CM indicate continuous memory status and are associated with continuous DTC B1085.

NOTE: When monitoring fault and/or resistance PIDs with the scan tool, it may take up to 2 seconds for the scan tool display to update.

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



PINPOINT TEST C: 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 taking 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.

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C18 CHECK CIRCUITS CR147 (GN/OG) AND RR147 (YE/VT) 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 load limiting retractor:
- C389-1, circuit CR147 (GN/OG), harness side and ground.
- C389-2, circuit RR147 (YE/VT), harness side and ground.




- Are resistances greater than 10,000 ohms?

Yes
GO to C21.

No
REPAIR circuit CR147 (GN/OG) or RR147 (YE/VT). GO to C26.

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C19 CHECK CIRCUITS RR147 (YE/VT) AND CR147 (GN/OG) 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 Load Limiting 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 load limiting 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 circuit RR147 (YE/VT) or CR147 (GN/OG). GO to C26.

No
GO to C21.

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C20 CONFIRM THE LOAD LIMITING RETRACTOR FAULT


NOTE: Make sure all restraint system components, sensor electrical connectors and the RCM electrical connectors are connected before carrying out the on-demand self test. If not, erroneous 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.
- 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 B1085 Fault PIDs.
- Refer to PID list in Normal Operation to view B1085 fault PIDs.
- Does the original RCM on-demand B1085 fault PID indicate a fault?

Yes
INSTALL a new driver or passenger load limiting retractor. GO to C26.

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 step and CHECK for causes of the intermittent fault in the areas previously worked in, particularly the pins and terminals of any electrical connector that were disconnected.

For 1085_28_CM (Seatbelt Load Limiter Driver Circuit Resist Low on Squib), 1085_29_CM (Seatbelt Load Limiter Driver Open), 1085_24_CM (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib) or 1085_25_CM (Seatbelt Load Limiter Front Passenger Open), GO to C22.

For 1085_31_CM (Seatbelt Load Limiter Driver Short to Ground) or 1085_27_CM (Seatbelt Load Limiter Front Passenger Short to Ground), GO to C24.

For 1085_30_CM (Seatbelt Load Limiter Driver Short to Battery) or 1085_26_CM (Seatbelt Load Limiter Front Passenger Short to Battery), GO to C25.

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C21 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 on-demand self test. If not, erroneous 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.
- 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 B1085 Fault PIDs.
- Refer to PID list in Normal Operation to view B1085 fault PIDs.
- Does the original RCM on-demand B1085 fault PID indicate a fault?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to C26.

No
In the process of diagnosing the fault, the fault condition has become intermittent. CHECK for causes of the intermittent fault in the areas previously worked in, particularly the pins and terminals of any electrical connector that were disconnected.

For 1085_28_CM (Seatbelt Load Limiter Driver Circuit Resist Low on Squib), 1085_29_CM (Seatbelt Load Limiter Driver Open), 1085_24_CM (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib) or 1085_25_CM (Seatbelt Load Limiter Front Passenger Open), GO to C22.

For 1085_31_CM (Seatbelt Load Limiter Driver Short to Ground) or 1085_27_CM (Seatbelt Load Limiter Front Passenger Short to Ground), GO to C24.

For 1085_30_CM (Seatbelt Load Limiter Driver Short to Battery) or 1085_26_CM (Seatbelt Load Limiter Front Passenger Short to Battery), GO to C25.

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C22 CHECK LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs FOR AN INTERMITTENT LOW RESISTANCE OR OPEN CIRCUIT


- If the fault PID or was reported for the driver load limiting retractor, monitor the following on the scan tool.
- D_LOAD (Seatbelt Load Limiter Resistance, Driver Side) resistance PID.
- 1085_28_OD (Seatbelt Load Limiter Driver Circuit Resist Low on Squib) and 1085_29_OD (Seatbelt Load Limiter Driver Open) on-demand fault PIDs.
- If the fault PID was reported for the passenger load limiting retractor, monitor the following on the scan tool.
- P_LOAD (Seatbelt Load Limiter Resistance, Passenger Side) resistance PID.
- 1085_24_OD (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib) and 1085_25_OD (Seatbelt Load Limiter Front Passenger Open) 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 an intermittent fault condition. 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 RCM on-demand B1085 fault PID indicate a fault is present or is resistance 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 C26.

No
GO to C23.

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C23 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 C26.

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

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 C26.

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C24 CHECK LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs FOR AN INTERMITTENT SHORT TO GROUND


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - PID.
- If the fault PID was reported for the driver load limiting retractor, monitor the 1085_31_OD (Seatbelt Load Limiter Driver Short to Ground) on-demand fault PID on the scan tool.
- If the fault PID was reported for the passenger load limiting retractor, monitor the 1085_27_OD (Seatbelt Load Limiter Front Passenger Short to Ground) on-demand fault PID on the scan tool.
- DIAGNOSTIC TIP: When monitoring fault PIDs with the scan tool, it may take up to 2 seconds for the scan tool display to update.
- Attempt to recreate the fault by wiggling connectors (including any in-line connectors) and flexing the wire harness.
- Does any RCM on-demand B1085 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 C26.

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

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 C26.

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C25 CHECK LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs FOR AN INTERMITTENT SHORT TO BATTERY


- If the fault PID was reported for the driver load limiting retractor, monitor the 1085_30_OD (Seatbelt Load Limiter Driver Short to Battery) on-demand fault PID.
- If the fault PID was reported for the passenger load limiting retractor, monitor the 1085_26_OD (Seatbelt Load Limiter Front Passenger Short to Battery) on-demand fault PID.
- Ignition ON.
- DIAGNOSTIC TIP: When monitoring fault PIDs with the scan tool, it may take up to 2 seconds for the scan tool display to update.
- Attempt to recreate the fault by wiggling the connectors (including any in-line connectors) and flexing the wire harness.
- Does any RCM on-demand B1085 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 C26.

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

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 C26.

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C26 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.
- Are any RCM and/or OCSM DTCs retrieved indicating a fault?

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 DTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

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