Possible Causes
OCS circuit fault could be caused by damaged wiring, terminals or connectors, faulty OCS module, faulty OCS mat sensor, faulty OCS pressure transducer 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. Retrieve, flag and record any continuous Diagnostic Trouble Codes (DTCs). See RETRIEVING FAULT CODES under DIAGNOSTICS. Flag DTC B2290. See BIT-MAPPED DIAGNOSTIC TROUBLE CODES under DIAGNOSTICS. Retrieve and record any flagged DTCs. Perform on-demand self-test. See ON-DEMAND SELF-TEST under DIAGNOSTICS. Retrieve and record any flagged DTCs. If flagged fault "?" was retrieved during on-demand self-test, multiple faults exist and all steps of diagnostic procedure must be performed. If DTC B2290 was retrieved during on-demand self-test, fault is hard.- For communication (COMM) fault, go to next step.
- For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS) under REMOVAL & INSTALLATION. Go to step 12 .
- For calibration fault, replace OCS system. Go to step 12 .
- For sensing element fault, replace OCS system. Go to step 12 .
- If DTC B2290 was not retrieved during on-demand self-test, fault is intermittent. Go to step 11 .
- Check ignition circuit for open
Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to OFF position. Turn ignition switch to RUN position. Access and disconnect OCS connector C3159A from OCS electronic control unit. See OCCUPANT CLASSIFICATION SENSOR (OCS) under REMOVAL & INSTALLATION. Position front seat in vehicle and reconnect seat floor harness connectors. Turn ignition switch to RUN position. Measure voltage between ground and harness side of OCS connector C3159A, terminal No. 4 (Dark Green/Light Blue wire, circuit No. 964). See Fig 1 . If voltage is 9-16 volts, go to next step. If voltage is not 9-16 volts, repair open in Dark Green/Light Blue wire. Go to step 12 . See WIRING DIAGRAMS . - Check ground circuit for open
Turn ignition switch to OFF position. Measure resistance between ground and OCS connector C3159A, terminal No. 9 (Pink/Orange wire, circuit No. 676). If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Pink/Orange wire. Go to step 12 . - Check for short to ground between OCS electronic control unit & RCM
Access and disconnect RCM connector C310A. See RESTRAINTS CONTROL MODULE under REMOVAL & INSTALLATION. Measure resistance between ground and harness side of OCS connector C3159A, terminal No. 5 (Dark Green/Violet wire, circuit No. 1556). Measure resistance between ground and harness side of OCS connector C3159A, terminal No. 10 (Dark Blue/Orange wire, circuit No. 1557). If resistance is more than one megohm in both circuits, go to next step. If resistance is less than one megohm in either circuit, repair short to ground in appropriate wire. Go to step 12 . - Check for short to battery between OCS electronic control unit & RCM
Turn ignition switch to RUN position. Measure voltage between ground and harness side of OCS connector C3159A, terminal No. 5 (Dark Green/Violet wire). Measure voltage between ground and harness side of OCS connector C3159A, terminal No. 10 (Dark Blue/Orange wire). If voltage is less than 0.2 volt in both circuits, go to next step. If voltage is more than 0.2 volt in either circuit, repair short to battery in appropriate wire. Go to step 12 . - Check circuit for open between OCS electronic control unit & RCM
Turn ignition switch to OFF position. Measure resistance between harness side of RCM connector C310A, terminal No. 1 and harness side of OCS connector C3159A, terminal No. 5 (Dark Green/Violet wire). 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 Dark Green/Violet wire. Go to step 12 . - Check circuit for open between OCS electronic control unit & RCM
Measure resistance between harness side of RCM connector C310A, terminal No. 2 and harness side of OCS connector C3159A, terminal No. 10 (Dark Blue/Orange wire). If resistance is less than 0.5 ohm, go to next step. If resistance is more than 0.5 ohm, repair open in Dark Blue/Orange wire. Go to step 12 . - Check circuit for short between OCS electronic control unit & RCM
Measure resistance between harness side of RCM connector C310A, terminal No. 1 (Dark Green/Violet wire) and harness side of OCS connector C3159A, terminal No. 10 (Dark Blue/Orange wire). If resistance is more than one megohm, go to next step. If resistance is less than one megohm, repair short between Dark Green/Violet and Dark Blue/Orange wires. Go to step 12 . - Check OCS
Reconnect RCM connector C310A. Install known-good OCS system. Zero OCS. See ZERO OCCUPANT CLASSIFICATION SENSOR (OCS) under DIAGNOSTICS. Perform on-demand self-test. Flag DTC B2290. Retrieve and record any flagged faults. If any faults were flagged against OCS, go to next step. If no faults were flagged against OCS, go to step 12 .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. Ensure both RCM connectors are connected. Perform on-demand self-test. Flag DTC B2290. Retrieve and record any flagged faults. If DTC B2290 was retrieved during on-demand self-test and "?" was flagged by scan tool, perform entire diagnostic test before replacing RCM. Replace RCM. Go to step 12 . If DTC B2290 was not retrieved during on-demand self-test, fault is corrected. Go to step 12 . - Check for intermittent fault
Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to ON position. Perform on-demand self-test. If DTC B2290 was retrieved during on-demand self-test, fault is hard. If flagged fault "?" was retrieved during on-demand self-test in step 1 , multiple faults exist and all steps of diagnostic procedure must be performed.- For communication (COMM) fault, go to step 2 .
- For internal (INT) fault, replace OCS system. See OCCUPANT CLASSIFICATION SENSOR (OCS) under REMOVAL & INSTALLATION. Go to next step.
- For calibration fault, replace OCS system. Go to next step.
- For sensing element fault, replace OCS system. Go to next step.
If DTC B2290 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.
