Turn Signals: Description and Operation

TURN SIGNAL/HAZARD FLASHER LAMPS
The FLASHER fuse in the fuse block underhood supplies battery positive voltage to the turn signal/hazard flasher module. The turn signal/hazard flasher module has ground at G200. The turn signal lamps may only be activated with the ignition switch in the ON or START position. The STRG CTRLS fuse in the fuse block underhood supplies battery positive voltage to the turn signal switch. When the turn signal switch is placed in either the left or right position, current flows from the turn signal switch assembly to the turn signal/hazard flasher module. The turn signal/hazard flasher module then sends an on-off voltage signal to either the left or right turn signals and the appropriate instrument panel cluster (IPC) indicator. When the IPC receives an input from either of the turn signals it starts to track vehicle mileage. When the IPC has determined that the vehicle has traveled over 1.6 km (1 mile) with one of the turn signals continuously engaged, it shall display the DIC message "Turn Signal On" and request the appropriate chime to notify the driver. The left turn signals have ground at G104 and at G402. The right turn signals have ground at G104 and G401.

The hazard flashers may be activated in any power mode. The hazard switch is permanently grounded through G200. When the driver turns ON the hazard switch the contacts in the switch close, grounding the hazard switch output circuit of the dash integration module (DIM). The turn signal/hazard flasher module then supplies battery voltage to all four turn signal lamps and IPC in an ON and OFF duty cycle. This illuminates the turn signal lamps in the same manner as explained above. When a THEFT is occurring, the dash integration module (DIM) provides a ground to the turn signal/hazard flasher module hazard switch signal circuit. This allows the hazard lamps to flash during theft detection.

The flash rate of the turn signal lamps is 90 flashes per minute. Each tail lamp assembly monitors the current among the LEDs. When 20 percent or more of the tail lamp LEDs fail, that tail lamp removes ground from the outage detection signal circuit. The turn signal/hazard flasher module will then increase the flash rate of the remaining turn signal lamps and the respective indicator to 180 flashes per minute.

REPEATER LAMPS
The repeater lamps are on export vehicles only. Each lamp is located in the front fender. The repeater lamps are used as additional turn signal lamps, and operate as described in the Turn Signal/Hazard Flasher Lamps description. The repeater lamps have ground at G104.