With the ignition switch in the ON position, ignition positive voltage is supplied to the inside rearview mirror. Battery positive voltage is supplied at all times to the reverse relay coil and the reverse relay switch. The powertrain control module (PCM) sends a Class 2 message to the rear integration module (RIM), indicating that the gear selector lever is in the REVERSE position. The RIM grounds the control circuit of the reverse relay. When the reverse relay is energized, battery positive voltage is supplied to the reverse input circuit of the inside rearview mirror. The inside rearview mirror will gradually change to a clear state as a result of the reverse input.
The left outside mirror element is controlled by the inside rearview mirror. The inside rearview mirror supplies ground to the ground circuit of the left outside rearview mirror element. The left outside mirror element darkens when the inside rearview mirror supplies 1.5 V to the signal circuit of the left outside mirror element and clears when the voltage is remove from the signal circuit of the left outside rearview mirror element.
The electronic compass includes a fluxgate magnetic field sensor and a microprocessor. The microprocessor receives inputs from the sensor, processes the inputs, and provides outputs to the compass display. The compass display then indicates the vehicle heading relative to the Earth's magnetic fields.