For 1990-2009 cars

### Speedometer and Odometer

The speedometer and the odometer operate in the following manner:

1. The vehicle speed sensor (VSS) is mounted in the transaxle.
2. The VSS generates an alternating current (AC) voltage signal. The signal has a frequency that is proportional to the speed of the vehicle.
3. The power train control module (PCM) monitors the signal from the VSS.
4. The PCM produces a 4000 pulse per mile signal on CKT 817 (DK GRN/WHT).
5. The signal switches to ground at a rate that is proportional to the speed of the vehicle.
6. The PCM provides this signal to the instrument cluster.
7. The instrument cluster uses the PCM output signal in order to operate the speedometer and the odometer.

### Fuel Gauge

The fuel level sender provides a signal to the instrument cluster. The signal is proportional to the fuel level. When the fuel tank is full, the fuel level sender resistance is 248 ohms. When the fuel tank is empty, the resistance is near 40 ohms. This instrument cluster converts the analog signal from the fuel level sender to a digital signal. The instrument cluster displays the fuel tank level.

### Temperature Gauge

The instrument cluster receives the engine coolant temperature data from the powertrain control module (PCM). The signal travels over the universal asynchronous receiving/transmitting (UART) serial data line. The instrument cluster converts the serial data. The instrument cluster displays the engine coolant temperature.