Possible Causes
WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
A left front seat belt buckle switch resistance out of range fault could be caused by damaged wiring, terminals, connectors, faulty seat belt buckle switch or faulty RCM.
- Check for hard or intermittent DTC
Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). See USING SCAN TOOL under DIAGNOSTICS. Turn ignition switch to ON position. Retrieve and record any continuous Diagnostic Trouble Codes (DTCs). See RETRIEVING FAULT CODES under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. If DTC B2435 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B2435 was not retrieved, fault is intermittent. Go to step 8 . - Check circuit for open between RCM & left front seat
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Access RCM and disconnect connector C310B. See RESTRAINTS CONTROL MODULE (RCM) under REMOVAL & INSTALLATION. Measure resistance between harness side of RCM connector C310B, terminal No. 25 and main harness side of left front seat connector C315, terminal No. 11 (White wire, circuit No. 8-JA54). See Figure & Fig 1 . If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in White wire. See WIRING DIAGRAMS . Go to step 9 . - Check circuit for open
Measure resistance between ground and main harness side of left front seat connector C315, terminal No. 4 (Black/Yellow wire, circuit No. 31-JA54). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Black/Orange wire. Go to step 9 . - Check circuit for open between left front seat & left front seat belt buckle switch
Disconnect left front seat belt buckle switch harness connector. Measure resistance in White wire between seat harness side of left front seat connector C315, terminal No. 11 and harness side of left front seat belt buckle switch connector. If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in White wire. Go to step 9 . - Check circuit for open between left front seat & left front seat belt buckle switch
Disconnect left front seat belt buckle switch harness connector. Measure resistance in Black/Yellow wire between seat harness side of left front seat connector C315, terminal No. 4 and harness side of left front seat belt buckle switch connector. If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Black/Yellow wire. Go to step 9 . - Check seat belt buckle switch
Turn ignition switch in OFF position. Connect connector C310B. Install known-good seat belt buckle switch and connect buckle switch harness connector. See SEAT BELT BUCKLE SWITCH ASSEMBLY under REMOVAL & INSTALLATION. Position left front seat in vehicle and connect under-seat harness connectors. DO NOT activate air bag system at this time. Connect negative battery cable. Perform on-demand self-test. If DTC B2435 was retrieved during on-demand self-test, go to next step. If DTC B2435 was not retrieved, fault is corrected. Go to step 9 .NOTE: Ensure all air bag system simulators, sensor electrical connectors and RCM electrical connectors are connected prior to carrying out on-demand self-test or erroneous faults may be set. - Confirm RCM fault
Turn ignition switch to OFF position. Install original seat belt buckle switch. Perform on-demand-self-test. If DTC B2435 was retrieved during on-demand self-test, replace RCM. Go to step 9 . If DTC B2435 was not retrieved during on-demand self-test, fault is corrected. Go to step 9 . - Check for intermittent DTC
Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Perform on-demand self-test. If DTC B2435 was retrieved during on-demand self-test, go to step 2 . If DTC B2435 was not retrieved during on-demand self-test, check for cause of intermittent fault. Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. Go to next step. - Check for additional DTCs
Refer to continuous DTCs recorded in step 1 . If any continuous DTCs were retrieved, go to diagnostic trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table. DO NOT clear any DTCs until all DTCs have been resolved. If no DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs. See CLEARING FAULT CODES under DIAGNOSTICS.