Possible Causes

Front crash sensor mounting or communications could be caused by damaged wiring on circuits 617 (Pink/Orange wire or 618 (Violet/Light Green wire), a damaged or inoperative crash sensor, incorrect mounting, or an internal RCM fault.

1. Check for hard or intermittent DTC
   
   Ensure ignition is off. Connect scan tool to DLC. See USING SCAN TOOL  under DIAGNOSTICS. Turn ignition switch to RUN position. Retrieve and record any continuous DTCs. See RETRIEVING FAULT CODES  under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST  under DIAGNOSTICS. If DTC B2225 or B2227 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B2225 or B2227 was not retrieved, fault is intermittent. Go to step  6 .
   NOTE: While measuring resistance in following test, operate various electrical systems such as radio, windows and blower motor.
2. Check circuits for short to battery
   
   Turn ignition off. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Leave negative battery cable disconnected. Access RCM and disconnect both harness connectors. See RESTRAINTS CONTROL MODULE  under REMOVAL & INSTALLATION. Turn ignition switch to RUN position. Measure resistance between RCM harness connector C310A, terminal No. 1 (White/Yellow wire) and RCM harness connector C310B, terminal No. 25 (Pink/Orange wire). See Figure . Measure resistance between RCM harness connector C310A, terminal No. 1 (White/Yellow wire) and RCM harness connector C310B, terminal No. 26 (Violet/Light Green wire). If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to voltage on appropriate wire, then go to step  7 .
3. Check sensor circuit
   
   Access front crash sensor and disconnect harness connector. See FRONT CRASH SENSOR  under REMOVAL & INSTALLATION. Measure resistance of Violet/Light Green wire between RCM harness connector C310B, terminal No. 26 and front crash sensor harness connector. Measure resistance of Pink/Orange wire between RCM harness connector C310B, terminal No. 25 and front crash sensor harness connector. If both resistances are less than 10 ohms, go to next step. If either resistance is more than 10 ohms, repair high resistance is appropriate wire, then go to step  7 .
4. Check front crash sensor.
   
   Reconnect negative battery cable. Measure resistance between a known good ground and front crash sensor mounting bolt. If resistance is less than 10 k/ohms, install a known good crash sensor, then go to next step. If resistance is more than 10 k/ohms, repair high resistance to ground at crash sensor mounting, then go to step  7 .
5. Check DTCs
   
   Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Perform on-demand self-test. If DTC B2225 or B2227 was retrieved during on-demand self-test, replace RCM, reinstall original crash sensor, then go to step  7 . If DTC B2225 or B2227 was not retrieved, system is functioning properly. Go to step  7 .
6. Check for intermittent fault
   
   Refer to continuous DTCs recorded in step  1 . If DTC retrieved in step  1 was a intermittent fault, check for cause of intermittent high resistance or short to battery on Pink/Orange and/or Violet/Light Green wires. Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. go to next step. If DTC retrieved in step  1 was not a intermittent fault, go to next step.
7. 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. 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.