Test O
PINPOINT TEST O: THE EXTERIOR LAMPS ARE INOPERATIVETest O1-O2:
Normal Operation
With the headlamp switch turned to the autolamp position, a battery voltage signal is sent to the vehicle security module through circuit 1399 (DB/WH). The vehicle security module then determines the amount of ambient light based on the input received from the photocell. The input signal is received through circuit 218 (WH/VT). When the ambient level has reached a point (determined by the internal programming of the vehicle security module), two internal relays are energized to supply power to the exterior lamps. Circuit 195 (TN/WH) supplies power to the internal parking lamp relay, which in turn supplies power to circuit 14 (BN) when energized. Circuit 1205 (BK) is the ground circuit for the photocell. When the headlamp switch is turned to the headlamp or parklamp position, voltage is supplied directly to circuit 14 (BN). Current then flows directly to all the exterior lights. Ground is provided to the bulbs through circuit 1205 (BK).
Possible Causes
- circuit 14 (BN) open
- circuit 195 (TN/WH) open
- circuit 1205 (BK) open
- vehicle security module
- headlamp switch