Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

DRL Ambient Light Sensor

The scan tool displays 0-5.0 volts. The voltage level varies based upon the ambient light level at the sensor. When light levels are high (Light), voltage will increase. When light levels are low (Dark), voltage will decrease. The BCM uses this information for automatic headlamp operation.