Method and apparatus for auto-negotiation of a programmable logic device for any of a plurality of communication protocols is described. A steady state torque estimator communicates with the vehicle data bus and generates a steady state engine torque signal. First circuit components which are low-heat-generating components with large height are located in the central window hole. The first and second conductive terminals are electrically connected to the rocker switch and the third conductive terminal is electrically connected to the ground line.