Hazard Warning Switch: Testing and Inspection
HAZARD SWITCHWARNING: TO AVOID PERSONAL INJURY OR DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, AIRBAG, OCCUPANT CLASSIFICATION SYSTEM, SEAT BELT TENSIONER, IMPACT SENSOR, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT.
The hard wired circuits of the hazard switch can be diagnosed using conventional diagnostic tools and methods. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the Forward Control Module (FCM), the Electromechanical Instrument Cluster (EMIC), the Controller Area Network (CAN) data bus or the electronic message inputs and outputs used to provide the electronic features of the hazard warning system. The most reliable, efficient and accurate means to diagnose this component requires the use of a diagnostic scan tool.
1. Remove the hazard switch from the Steering Control Module (SCM).
2. Using a multi-meter, test the continuity between the two terminals of the switch. There should be continuity when the switch push button is in its unlatched (raised) position, and no continuity when the switch push button is in its latched (lowered) position.
3. If the switch fails any of the tests, replace the faulty hazard switch as required.