DTC B2648: Ambient Light Sensor Circuit High: Notes

TBC module monitors circuit No. 278 (White wire) to determine when headlights need to be turned on when headlight switch is in AUTO mode. See WIRING DIAGRAMS  . When circuit to TBC module is shorted to battery voltage, DTC will set.

Conditions for setting DTC:

• Circuit No. 278 (White wire) is shorted to battery voltage.
• System voltage 9-16 volts.
• Conditions met for .5 second.