Fixed most of my LS400 instrument issues (lights, gas gauge, sticking needles) but the speedometer is linearly low on actual speed (error increases as speed increases). I know this because of my GPS. I suspect that the electrolytic caps on the meter board (C2, C3, C4) attached to the needle movement may be the culprit since they are the same age as those that have failed on the lights and gas gauge circuits. I believe this speedometer design uses a hall effect sensor on the transmission that sends pulses to the meter board where a microprocessor counts the pulses and drives a stepper motor attached to the needle. This seems to be the typical design used for analog meters today. Does anyone have a schematic of the meter board or have experience with this problem?