Pinpoint Test AA: LFC 53/DTC B2691 - Seat Belt Buckle Switch Circuit Fault - Front Driver Side: Testing
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Most faults are due to connector and/or wiring concerns. Carry out a thorough Inspection and Verification before proceeding with the pinpoint test.
- AA1 CHECK FOR CONTINUOUS OR ON-DEMAND DTCs WARNING: Restraint system diagnostic tools are for service only. Tools must be removed prior to operating the vehicle over the road. Failure to remove restraint system diagnostic tools could result in injury and possible violation of vehicle safety standards.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 these instructions may result in the inadvertent deployment of the safety canopy and risk of personal injury.WARNING: Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.WARNING: The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.WARNING: Never probe the electrical connector on a safety canopy module. Doing so can result in safety canopy deployment.NOTE: If a seat equipped with a supplemental restraint system (SRS) component is being serviced, the SRS must be depowered.NOTE: After diagnosing or repairing an SRS, the restraint system diagnostic tools must be removed before operating the vehicle over the road.NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Enter the following diagnostic mode on the scan tool: Retrieve/Record Continuous DTCs.
- Was the DTC B2691 retrieved during the on-demand self test?
- 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. GO to AA2.
- No : This is an intermittent fault. The fault condition is not present at this time. GO to AA7.
- AA2 CHECK CIRCUIT 85 (BN/LB) FOR AN OPEN BETWEEN THE RCM AND THE DRIVER SAFETY BELT BUCKLE SWITCH
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect: RCM C310a and C310b.
- Disconnect: Driver Safety Belt Buckle Switch C3065.
- Measure the resistance between RCM C310b pin 25, circuit 85 (BN/LB), harness side and driver safety belt buckle switch C3065 pin 1, circuit 85 (BN/LB), harness side.
- Is the resistance less than 0.5 ohm?
- Yes : GO to AA3.
- No : REPAIR circuit 85 (BN/LB). GO to AA8.
- AA3 CHECK CIRCUIT 1203 (BK/LB) FOR AN OPEN
- Measure the resistance between driver safety belt buckle switch C3065 pin 2, circuit 1203 (BK/LB), harness side and ground.
- Is the resistance less than 0.5 ohm?
- Yes : GO to AA4.
- No : REPAIR circuit 1203 (BK/LB). GO to AA8.
- AA4 CHECK CIRCUIT 85 (BN/LB) FOR A SHORT TO VOLTAGE
- Disconnect: Driver Seat Side Air Bag Module C3226 (Vehicles with seat side air bag modules).
- Connect: Restraint System Diagnostic Tool 418-133 to Driver Seat Side Air Bag Module C3226 (Vehicles with seat side air bag modules).
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Key in ON position.
- Measure the voltage between driver safety belt buckle switch C3065 pin 1, circuit 85 (BN/LB), harness side and ground.
- Is the voltage less than 0.2 volt?
- Yes : GO to AA5.
- No : REPAIR circuit 85 (BN/LB). GO to AA8.
- AA5 CHECK THE DRIVER SAFETY BELT BUCKLE SWITCH
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Connect: RCM C310a and C310b.
- Install a known good driver safety belt buckle assembly. REFER to SAFETY BELT SYSTEM .
- Connect: Driver Safety Belt Buckle Switch C3065.
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Was DTC B2691 retrieved during the on-demand self test?
- Yes : GO to AA6.
- No : Fault corrected. GO to AA8.
- AA6 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.
- Key in OFF position.
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Reinstall the original driver safety belt buckle assembly. REFER to SAFETY BELT SYSTEM .
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Was DTC B2691 retrieved during the on-demand self test?
- Yes : INSTALL a new RCM. REFER to RESTRAINTS CONTROL MODULE (RCM) . GO to AA8.
- No : CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. GO to AA8.
- AA7 CHECK FOR AN INTERMITTENT FAULT
- Key in OFF position.
- For vehicles with seat side air bags:
- Depower the system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Disconnect the driver seat side air bag module C3226.
- Connect restraint system diagnostic tool 418-133 to driver seat side air bag module C3226.
- Repower the system. Do not prove out the system at this time. Refer to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING .
- Enter the following diagnostic mode on the scan tool: On-Demand Self Test.
- Was DTC B2691 retrieved during the on-demand self test?
- Yes : GO to AA2.
- No : CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. REPAIR any intermittent concerns found. GO to AA8.
- AA8 CHECK FOR ADDITIONAL DTCs
- Refer to the continuous DTCs recorded during Step AA1.
- Were any continuous DTCs retrieved during Step AA1 ?
- Yes : Do not clear any DTCs until all DTCs have been resolved. GO to the RESTRAINTS CONTROL MODULE (RCM) DIAGNOSTIC TROUBLE CODE (DTC) TABLE for pinpoint test direction.
- No : RECONNECT the system. If previously directed to deactivate the system, REACTIVATE the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEACTIVATION AND REACTIVATION . REPOWER the system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM (SRS) DEPOWERING AND REPOWERING . PROVE OUT the system. CLEAR all DTCs.