Pinpoint Test D: LFC 18/B1884
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests
Pinpoint Test D: LFC 18/B1884
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
NOTE: The Passenger Air Bag Deactivation (PAD) indicator is part of the hazard switch assembly and cannot be serviced separately.
Normal Operation
When the ignition is in the ON position, the PAD indicator prove-out period is initiated by the Restraints Control Module (RCM). The RCM briefly activates the PAD indicator by supplying a ground on the PAD indicator circuit to verify operation. Refer to Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) Description and Operation.
If the RCM detects an open or short to ground on the PAD indicator circuit, it will store DTC B1884 in memory and flash Lamp Fault Code (LFC) 18 on the air bag warning indicator.
- DTC B1884 PAD Warning Lamp Circuit Failure - If the RCM detects an open circuit or short to ground on the PAD indicator circuit, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PAD indicator
- RCM
PINPOINT TEST D: LFC18/DTC B1884
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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D1 RETRIEVE RCM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was RCM DTC B1884 retrieved on-demand during the self test?
Yes
If the PAD indicator does not illuminate, GO to D2.
If the PAD indicator does illuminate, GO to D5.
No
This is an intermittent fault when present as a CMDTC only. The fault condition is not present at this time. GO to D9.
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D2 CHECK THE RCM CONNECTOR
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C2041a and C2041b.
- Inspect the RCM C2041a component side for damaged camming beams.
- NOTE: The shorting bars can be accessed by prying out the cover from the harness side of the connector. Do not remove or defeat the shorting bars.
- Inspect RCM C2041a harness side for worn, damaged or dislodged shorting bars. Inspect for foreign material. Inspect for pushed out connector terminals.
- Were any RCM connector concerns found?
Yes
CORRECT the connector concerns. GO to D10.
No
GO to D3.
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D3 CHECK CIRCUIT 1632 (TN/LB) FOR SHORT TO GROUND
- Connect: RCM C2041a and C2041b.
- Disconnect: PAD Indicator C2039.
- Measure the resistance between PAD indicator C2039-2, circuit 1632 (TN/LB), harness side and ground.
- Is resistance greater than 10,000 ohms?
Yes
GO to D8.
No
GO to D4.
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D4 CHECK THE RCM
- Disconnect: RCM C2041a and C2041b.
- Measure the resistance between RCM C2041a-15, circuit 1632 (TN/LB), component side and ground.
- Is resistance greater than 10,000 ohms?
Yes
REPAIR circuit 1632 (TN/LB). GO to D10.
No
GO to D8.
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D5 CHECK THE PAD INDICATOR
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- 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.
- Is the PAD indicator ON?
Yes
GO to D8.
No
GO to D6.
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D6 CHECK CIRCUIT 1632 (TN/LB) FOR AN OPEN
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: PAD Indicator C2039.
- Measure the resistance between PAD indicator C2039-2, circuit 1632 (TN/LB), harness side and RCM C2041a-15, circuit 1632 (TN/LB), harness side.
- Is resistance less than 0.5 ohm?
Yes
GO to D7.
No
REPAIR circuit 1632 (TN/LB). GO to D10.
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D7 CHECK CIRCUIT 1850 (YE) FOR AN OPEN
- 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 PAD indicator C2039-3, circuit 1850 (YE), harness side and ground.
- Is voltage greater than 10 volts?
Yes
INSTALL a new PAD indicator. REFER to Passenger Air Bag Deactivation (PAD) Indicator Service and Repair.
GO to D10.
No
REPAIR circuit 1850 (YE). GO to D10.
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D8 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.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Connect: PAD Indicator C2039 (if previously disconnected).
- Connect: RCM C2041a and C2041b (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.
- Was RCM DTC B1884 retrieved on-demand during the self test?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to D10.
No
CHECK for causes of intermittent open or short to ground on circuit 1632 (TN/LB). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition frequently. ACTIVATE other systems in the same wire harness. 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 D10.
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D9 CHECK FOR AN INTERMITTENT FAULT
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was RCM DTC B1884 retrieved on-demand during the self test?
Yes
GO to D2.
No
CHECK for causes of intermittent open or short to ground on circuit 1632 (TN/LB). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition frequently. ACTIVATE other systems in the same wire harness. 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 D10.
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D10 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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