Circuit/System Testing - Without UGN

Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at the S70A Steering Wheel Controls Switch - Left Lower, ignition ON.
Verify a test lamp illuminates when placed between the PWM voltage control terminal 4 and ground.
NOTE:
Verify vehicle interior dimming control is set all the way bright.
- If test lamp does not illuminate
  Refer to Interior Backlighting Malfunction
- If the test lamp illuminates
Connect a test lamp between the control circuit terminal 4 and control circuit terminal 5.
Verify the test lamp turns ON and OFF when commanding the Lane Departure Warning Indicator On and Off with a scan tool.
- If the test lamp is always OFF
1. Ignition OFF, disconnect the harness connector at the B174W Frontview Camera - Windshield.
2. Test for infinite resistance between the voltage circuit and ground.
  - If less than infinite resistance, repair the short to ground in the circuit.
  - If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the B174W Frontview Camera - Windshield.
- If the test lamp is always ON
1. Ignition OFF, disconnect the harness connector at the K109 Active Safety Control Module, ignition ON.
2. Test for less than 1 V between the voltage circuit and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the B174W Frontview Camera - Windshield.
- If the test lamp turns ON and OFF
Test or replace the S70A Steering Wheel Controls Switch - Left Lower.