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Fog Lights Will Not Turn On

NOTE: Perform EXTERIOR LIGHT TEST 1A  before proceeding with this test. For connector terminal identification and wiring diagrams, see BODY CONTROL COMPUTER - INTRODUCTION. Perform VERIFICATION TEST: VER-2A  after each repair.
CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
  1. Turn fog light on with headlights on. Using scan tool, select SENSORS. Read headlight switch voltage. If scan tool does not display HEADLIGHT SWITCH VOLTAGE: 3.0 volts (approximately), replace headlight switch. If scan tool displays HEADLIGHT SWITCH VOLTAGE: 3.0 volts (approximately), go to next step.
  2. Using scan tool, actuate fog light relay. If relay can be heard clicking during actuation, go to next step. If relay cannot be heard during actuation, go to step  5.
  3. Remove fog light relay from junction block. See Figure. Using external voltmeter, measure voltage between ground and terminal "D" (fused B+ circuit) on relay socket. If voltage is 10 volts or less, replace junction block. If voltage is greater than 10 volts, go to next step.
  4. Connect jumper wire between terminals "B" (low beam relay output circuit) and "D" on fog light relay socket. If fog lights illuminate, replace relay. If fog lights do not illuminate, repair open fog light relay output circuit.
  5. Stop fog light actuation. Turn on headlights and attempt to turn on high beam headlights. If high beam headlights operate, go to next step. If high beam headlights do not operate, repair open fused B+ circuit from Power Distribution Center fuse "C".
  6. Inspect junction block fuse No. 16. If fuse is open, go to step  10. If fuse is okay, go to next step.
  7. Remove fog light relay from junction block. Using external voltmeter, measure voltage between ground and terminal "C" (fused B+ circuit) on relay socket. If voltage is 10 volts or less, repair open fused B+ circuit. If voltage is more than 10 volts, go to next step.
  8. Connect test light between terminals "A" and "C" on fog light relay socket. Using scan tool, actuate fog light relay. If test light flashes, replace relay. If test light does not flash, go to next step.
  9. Remove Body Control Module (BCM) from junction block. BCM is mounted to junction block located behind left end cap of instrument panel. See Figure.
  10. Remove fog light relay. Using external ohmmeter, measure resistance between ground and terminal "B" on relay socket. If resistance is less than 10 ohms, repair shorted fused B+ circuit. Replace fuse No. 16. If resistance is 10 ohms or greater, replace fuse No. 16.
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