Auto-On Headlights System On-Vehicle Inspection

Turn ignition switch to ON position and release parking brake and turn lighting switch to OFF position.
Cover the sensor lens of auto-on headlight controller (1) with a hand and check headlights come ON after 5 seconds. If headlights do not come ON, go to Step 4 .

Fig 1: Checking Headlights Come On, By Covering Sensor
Courtesy of SUZUKI OF AMERICA CORP.
Light the sensor lens of auto-on headlight controller (1) with a light (2) and check headlights go out after 20 seconds. If headlights do not go out, go to Step 4).
If check result is of Step 1) to 3) is OK, this system is OK.

Fig 2: Checking Headlights Go Out, By Shining light Into Sensor
Courtesy of SUZUKI OF AMERICA CORP.
Disconnect auto-on headlights controller coupler (1) with ignition switch OFF.
Check the voltage between terminals are as follows.
If check result is not satisfactory, repair and recheck.
1. Auto-on headlight system circuit specification
2. Terminal G34-6 and G34-1 (ignition switch OFF): 0 V
3. Terminal G34-6 and G34-1 (Ignition switch ON): 10 - 14 V
4. Terminal G34-6 and G34-4: 10 - 14 V
5. Terminal G34-6 and G34-5: 10 - 14 V
  
  Fig 3: Identifying Auto-On Headlight Controller Coupler (Terminals)
  Courtesy of SUZUKI OF AMERICA CORP.
If check result of step 5) is OK, replace controller and recheck.