To adapt the TJ speed sensor to the Tacoma speedo cluster and to calibrate the speedometer we used an Abbott Electronic Ratio Adapter (ERA). This small unit provides the ability to choose a multiplier to account for any combination of gear ratios and tire size to provide accurate speedometer readout. The ERA accepts the pulsed signal from the TJ sensor and modifies it to the correct pulse rate needed for the speedo. We mounted the unit in the passenger side kick panel where it is accessible. Using a speed run and checking displayed speed versus that on a handheld GPS, we calculated our error and adjusted the internal ratio switches to obtain the correct multiplier we needed.