The DRL system includes the DRL relay, the high beam headlamps, and the DRL logic which is located within the I/P cluster on the speedometer printed circuit board (PCB). The system uses the ignition 1, park brake, high beams, and headlamps ON inputs to determine whether to turn DRL ON or OFF.
The DRL system illuminates the high beam headlamps at half intensity to increase vehicle visibility during the daylight hours. The half intensity is achieved by using the DRL relay to connect the 2 high beam headlamps in a series circuit, instead of the parallel circuit during regular high beam operation.
Under any of the following conditions DRL will be turned OFF:
| • | The parking brake is applied. |
| • | The ignition is not in the RUN position. |
| • | The headlamp input is grounded, when low or high beam headlamps are ON. |
| • | The high beam input is grounded, when in flash to pass or high beam headlamps ON mode. |
| • | If the left high beam is open. This is detected at the high beam input (pin N). When the DRL is active this input should be at half battery voltage. If the left high beam is open then the input will be pulled to ground when the DRL relay is energized. The DRL logic will cycle the relay several times to verify the condition and then disable DRL operation. |
| • | If the right high beam is open, the DRL will be OFF. |
However if both high beam headlamps are open, the DRL telltale will be illuminated because the logic cannot detect this condition.
