Abstract: An apparatus for monitoring operation a vehicle apparatus includes sensors for sensing G-forces on the vehicle and for generating output signals proportional to a forward G-force, a reverse G-force, a left direction G-force, and a right direction G-force on the vehicle. The apparatus permits an authorized user to set a selected maximum G-force limit for each direction. The apparatus stores G-force output signals generated by the sensors which are higher than the maximum selected limit for each direction. An oven heats each sensor to a substantially constant predetermined temperature, thereby improving the accuracy of the output signals from the sensor upon fluctuation of an ambient temperature adjacent the apparatus. The apparatus detects when the apparatus has been disconnected from a power supply to alert an owner of the vehicle that the vehicle may have been driven without the monitoring apparatus in operation.