Possible Causes

Code 45 will set if there is a poor connection due to loose mounting, dirt, or corrosion at left front impact sensor mounting surface. Code 45 will also set if there is an open or damaged wire between terminal No. 21 of diagnostic monitor connector and left front impact sensor, or inside left front impact sensor.

1. Verify Condition  - Turn ignition on. Check for fault codes. If Code 45 is flashing, go to step 2). If Code 45 is not flashing, check connectors, wiring, splices and crimps for an intermittent problem. DO NOT  proceed with diagnostic test unless code is flashing. Doing so will result in needless replacement of system components.
2. Deactivate System  - Deactivate air bag system. See COMPLETE SYSTEM DEACTIVATION  under DISABLING & ACTIVATING AIR BAG SYSTEM. Leave positive battery cable disconnected. Disconnect diagnostic monitor. Diagnostic monitor is located on left side of steering column under instrument panel. Set ohmmeter to 200 ohms scale. Measure resistance between terminals No. 21 (Purple/Light Blue wire) and No. 3 (Black/White wire) of diagnostic monitor connector. If resistance is more than 2 ohms, go to step 3). If resistance is less than 2 ohms, replace diagnostic monitor.
3. Check Front Center Impact Sensor Ground  - Disconnect center front impact sensor. Measure resistance between Purple/Light Blue wire in sensor connector and ground. If resistance is less than 2 ohms, inspect circuit between terminal No. 21 and sensor. Also, check all terminal crimps and splices. Repair as necessary. If resistance is more than 2 ohms, remove sensor. Clean sensor mounting surfaces. Reinstall sensor. Go to step 4).
4. Measure Resistance Of Sensor Ground  - Measure resistance between Purple/Light Blue wire in impact sensor connector and ground. If resistance is less than 2 ohms, circuit is okay. Cleaning sensor mounting surfaces in step 3) corrected the problem. If resistance is more than 2 ohms, replace left front impact sensor.