Pinpoint Test G: LFC 18/DTC B1884
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests
Pinpoint Test G: LFC 18/DTC B1884
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Normal Operation
The Restraints Control Module (RCM) has the ability to deactivate the passenger air bag under certain conditions. When the passenger air bag is deactivated, the Passenger Air Bag Deactivation (PAD) warning indicator will be illuminated.
The RCM monitors the PAD switch warning indicator for an open or short to ground. If the RCM detects an open (indicator does not illuminate) or short to ground (indicator illuminated continuously) on the PAD warning indicator circuit, it will store a DTC B1884 in memory and send a message to the Instrument Cluster (IC) module to flash Lamp Fault Code (LFC) 18 (or higher priority code if one exists) on the air bag warning indicator.
- DTC B1884 (PAD Warning Lamp Circuit Failure) - If the RCM detects an open circuit or short to ground when the indicator is not active for greater than 2.2 seconds on the PAD indicator circuit, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connector
- Smart Junction Box (SJB) fuse
- PAD indicator
- PAD switch
- RCM
PINPOINT TEST G: LFC 18/DTC B1884
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: 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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G1 RETRIEVE RCM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC B1884 retrieved on-demand during self-test?
Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test.
If the PAD indicator does not illuminate, GO to G2.
If the PAD indicator does illuminate, GO to G4.
No
This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to G5.
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G2 CHECK PAD SWITCH IGNITION CIRCUIT FOR VOLTAGE
- Ignition OFF.
- Disconnect: PAD Switch C2099.
- Ignition ON.
- Measure the voltage between PAD switch C2099-1, circuit CBP32 (GN/VT), harness side and ground.
- Is any voltage present?
Yes
VERIFY the Smart Junction Box (SJB) fuse 32 (10A) is OK. If OK, REPAIR circuit CBP32 (GN/VT). GO to G6.
If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. GO to G6. Diagrams By Number
No
GO to G3.
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G3 CHECK CIRCUIT RR116 (BN/GN) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between RCM C310A-22, circuit RR116 (BN/GN), harness side and PAD switch C2099-2, circuit RR116 (BN/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new PAD switch. REFER to Passenger Air Bag Deactivation (PAD) Switch Service and Repair. GO to G6.
No
REPAIR circuit RR116 (BN/GN). GO to G6.
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G4 CHECK CIRCUIT RR116 (BN/GN) FOR A SHORT TO GROUND
- 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.
- Turn the ignition OFF and wait one minute before disconnecting any SRS component.
- Disconnect: PAD Switch C2099.
- Measure the resistance between PAD switch C2099-2, circuit RR116 (BN/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to G6.
No
REPAIR circuit RR116 (BN/GN). GO to G6.
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G5 CHECK FOR AN INTERMITTENT FAULT
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC B1884 retrieved on-demand during self-test?
Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self-test. GO to G2.
No
CHECK for causes of the intermittent fault on circuit CR224 (GN). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. 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 G6.
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G6 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.
- If previously directed to deactivate the SRS, reactivate the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Deactivation and Reactivation Supplemental Restraint System (SRS) Deactivation and Reactivation.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Are any RCM DTCs retrieved indicating a fault?
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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