Rear Fog Light Control Unit Input Test

With Front and Rear Fog Lights


1.Remove the driver's dashboard under cover.

2.Disconnect the 5P connector (A) from the rear fog light control unit (B).

 

3.Inspect the connector and socket terminals to be sure they are all making good contact.

  • If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
  • If the terminals are OK, go to 4.

4.With the connector still disconnected, make these input tests at the connector.

  • If any test indicates a problem, find and correct the cause, then recheck the system.
  • If all the input tests prove OK, replace the rear fog light control unit.

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained 
RED/YEL Headlight switch ON Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 13 (20 A) fuse in the under-hood fuse/relay box
  • Blown No. 18 (10 A) fuse in the under-dash fuse/relay box
  • Faulty rear fog light relay
  • Faulty combination light switch
  • An open in the wire
 
WHT Headlight switch ON Jump No. 1 terminal to the No. 2 terminal:
The rear fog light should come on. 
  • Poor ground (G401)
  • Blown rear fog light bulb
  • An open in the wire
 
BLU/RED Rear fog light switch ON Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 9 (10 A) fuse in the under-hood fuse/relay box
  • Faulty taillight relay
  • Faulty combination light switch
  • An open in the wire
 
BLK Under all conditions Check for continuity to ground:
There should be continuity. 
  • Poor ground (G401)
  • An open in the wire