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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 >> C1-C17

C1-C17




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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C1 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 B1085 Fault PIDs.
- Refer to PID list in Normal Operation to view B1085 fault PIDs.
- Do any RCM DTC B1085 fault PIDs indicate a fault?

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

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

For 1085_28_OD (Seatbelt Load Limiter Driver Circuit Resist Low on Squib), GO to C2.

For 1085_29_OD (Seatbelt Load Limiter Driver Open), GO to C2.

For 1085_31_OD (Seatbelt Load Limiter Driver Short to Ground), GO to C8.

For 1085_30_OD (Seatbelt Load Limiter Driver Short to Battery), GO to C10.
For 1085_24_OD (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib), GO to C11.

For 1085_25_OD (Seatbelt Load Limiter Front Passenger Open), GO to C11.

For 1085_27_OD (Seatbelt Load Limiter Front Passenger Short to Ground), GO to C17.

For 1085_26_OD (Seatbelt Load Limiter Front Passenger Short to Battery), GO to C19.

No
This is an intermittent fault when present as a continuous memory DTC only (DTC not retrieved on-demand). The fault condition is not present at this time.

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

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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C2 CHECK THE DRIVER LOAD LIMITING RETRACTOR RESISTANCE PID (D_LOAD)


- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - PID.
- Enter the following diagnostic mode on the scan tool: D_LOAD (Seatbelt Load Limiter Resistance, Driver Side) Resistance PID.
- Does resistance PID value read between 1.50 and 3.04 ohms?

Yes
GO to C21.

No
GO to C3.

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C3 CHECK THE DRIVER LOAD LIMITING RETRACTOR RESISTANCE PID (D_LOAD) WHILE CARRYING OUT A HARNESS TEST


- Continue monitoring the D_LOAD (Seatbelt Load Limiter Resistance, Driver Side) resistance PID while carrying out a harness test of the driver load limiting retractor circuits and accessible connectors (including any in-line connectors), by wiggling connectors and flexing the wire harness.
- Does resistance PID value read between 1.50 and 3.04 ohms while carrying out a harness test?

Yes
DEPOWER the SRS and REPAIR the connector, terminals or wire harness as needed. Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

GO to C26.

No
If the driver load limiting retractor resistance PID is less than 1.50 ohms, GO to C4.

If the driver load limiting retractor resistance PID is greater than 3.04 ohms, GO to C6.

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C4 CHECK THE DRIVER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_28_OD AND 1085_29_OD) FOR LOW RESISTANCE AND OPEN


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: Driver Load Limiting Retractor C354.
- 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_28_OD (Seatbelt Load Limiter Driver Circuit Resist Low on Squib)
- 1085_29_OD (Seatbelt Load Limiter Driver Open)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the driver load limiting retractor disconnected, an open circuit fault would normally be retrieved.
- Did the driver load limiting retractor on-demand fault PIDs change from indicating a low resistance to an open circuit fault?

Yes
GO to C20.

No
GO to C5.

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C5 CHECK FOR A SHORT BETWEEN DRIVER LOAD LIMITING RETRACTOR CIRCUITS CR146 (GY/VT) AND RR146 (BU/BN)


- 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 driver load limiting retractor C354-1, circuit CR146 (GY/VT), harness side and C354-2, circuit RR146 (BU/BN), harness side.




- Is resistance greater than 10,000 ohms?

Yes
GO to C21.

No
REPAIR circuits CR146 (GY/VT) and RR146 (BU/BN). GO to C26.

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C6 CHECK THE DRIVER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_29_OD AND 1085_28_OD) FOR AN OPEN AND LOW RESISTANCE


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: Driver Load Limiting Retractor C354.
- Connect a fused jumper wire between driver load limiting retractor C354-1, circuit CR146 (GY/VT), harness side and C354-2, circuit RR146 (BU/BN), 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_28_OD (Seatbelt Load Limiter Driver Circuit Resist Low on Squib)
- 1085_29_OD (Seatbelt Load Limiter Driver Open)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the driver load limiting retractor circuits shorted together, a low resistance fault would normally be retrieved.
- Did the driver load limiting retractor on-demand fault PIDs change from indicating an open circuit to a low resistance fault?

Yes
GO to C20.

No
GO to C7.

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C7 CHECK CIRCUITS CR146 (GY/VT) AND RR146 (BU/BN) 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 driver load limiting retractor C354.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310b, harness side and driver load limiting retractor C354, harness side using the following chart.









- Are resistances less than 0.5 ohm?

Yes
GO to C21.

No
REPAIR circuit CR146 (GY/VT) or RR146 (BU/BN). GO to C26.

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C8 CHECK THE DRIVER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_29_OD AND 1085_31_OD) FOR AN OPEN AND SHORT TO GROUND


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: Driver Load Limiting Retractor C354.
- 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_29_OD (Seatbelt Load Limiter Driver Open)
- 1085_31_OD (Seatbelt Load Limiter Driver Short to Ground)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the driver load limiting retractor disconnected, an open circuit fault would normally be retrieved.
- Did the driver load limiting retractor on-demand fault PIDs change from indicating a short to ground to an open circuit fault?

Yes
GO to C20.

No
GO to C9.

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C9 CHECK CIRCUITS CR146 (GY/VT) AND RR146 (BU/BN) 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 driver load limiting retractor:
- C354-1, circuit CR146 (GY/VT), harness side and ground.
- C354-2, circuit RR146 (BU/BN) and ground.




- Are resistances greater than 10,000 ohms?

Yes
GO to C21.

No
REPAIR circuit CR146 (GY/VT) or RR146 (BU/BN). GO to C26.

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C10 CHECK CIRCUITS CR146 (GY/VT) AND RR146 (BU/BN) 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 Load Limiting Retractor C354.
- 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 driver load limiting retractor:
- C354-1, circuit CR146 (GY/VT), harness side and ground.
- C354-2, circuit RR146 (BU/BN), harness side and ground.




- Is voltage present on either circuit?

Yes
REPAIR circuit CR146 (GY/VT) or RR146 (BU/BN). GO to C26.

No
GO to C21.

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C11 CHECK THE PASSENGER LOAD LIMITING RETRACTOR RESISTANCE PID (P_LOAD)


- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - PID.
- Enter the following diagnostic mode on the scan tool: P_LOAD (Seatbelt Load Limiter Resistance, Passenger Side) Resistance PID.
- Does resistance PID value read between 1.50 and 3.04 ohms?

Yes
GO to C21.

No
GO to C12.

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C12 CHECK THE PASSENGER LOAD LIMITING RETRACTOR RESISTANCE PID (P_LOAD) WHILE CARRYING OUT A HARNESS TEST


- Continue monitoring the P_LOAD (Seatbelt Load Limiter Resistance, Passenger Side) resistance PID while carrying out a harness test of the passenger load limiting retractor circuits and accessible connectors (including any in-line connectors), by wiggling connectors and flexing the wire harness.
- Does resistance PID value read between 1.50 and 3.04 ohms while carrying out the harness test?

Yes
DEPOWER the SRS and REPAIR the connector, terminals or wire harness as needed. Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

GO to C26.

No
If the passenger load limiting retractor resistance PID is less than 1.50 ohms, GO to C13.

If the passenger load limiting retractor resistance PID is greater than 3.04 ohms, GO to C15.

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C13 CHECK THE PASSENGER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_24_OD AND 1085_25_OD) FOR LOW RESISTANCE AND OPEN


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 Load Limiting 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_24_OD (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib)
- 1085_25_OD (Seatbelt Load Limiter Front Passenger Open)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the passenger load limiting retractor disconnected, an open circuit fault would normally be retrieved.
- Did the passenger load limiting retractor on-demand fault PIDs change from indicating a low resistance to an open circuit fault?

Yes
GO to C20.

No
GO to C14.

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C14 CHECK FOR A SHORT BETWEEN PASSENGER LOAD LIMITING RETRACTOR CIRCUITS RR147 (YE/VT) AND CR147 (GN/OG)


- 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 C389-2, circuit RR147 (YE/VT), harness side.




- Is resistance greater than 10,000 ohms?

Yes
GO to C21.

No
REPAIR circuits CR147 (GN/OG) and RR147 (YE/VT). GO to C26.

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C15 CHECK THE PASSENGER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_25_OD AND 1085_24_OD) FOR LOW RESISTANCE AND OPEN


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 Load Limiting Retractor C389.
- Connect a fused jumper wire between passenger load limiting 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 (Seatbelt Load Limiter Front Passenger Circuit Resist Low on Squib)
- 1085_25_OD (Seatbelt Load Limiter Front Passenger Open)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the passenger load limiting retractor circuits shorted together, a low resistance fault would normally be retrieved.
- Did the passenger load limiting retractor on-demand fault PIDs change from indicating an open circuit to a low resistance fault?

Yes
GO to C20.

No
GO to C16.

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C16 CHECK CIRCUITS CR147 (GN/OG) AND RR147 (YE/VT) 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 load limiting retractor C389.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310b, and passenger load limiting retractor C389, harness side using the following chart.









- Are resistances less than 0.5 ohm?

Yes
GO to C21.

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

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C17 CHECK THE PASSENGER LOAD LIMITING RETRACTOR CIRCUIT FAULT PIDs (1085_27_OD AND 1085_25_OD) FOR SHORT TO GROUND AND OPEN


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 Load Limiting 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 (Seatbelt Load Limiter Front Passenger Open)
- 1085_27_OD (Seatbelt Load Limiter Front Passenger Short to Ground)
- DIAGNOSTIC TIP: When viewing DTC B1085 on-demand fault PIDs with the passenger load limiting retractor disconnected, an open circuit fault would normally be retrieved.
- Did the passenger load limiting retractor on-demand fault PIDs change from indicating a short to ground to an open circuit fault?

Yes
GO to C20.

No
GO to C18.

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