Hello, We have a Cat 120M S/N NJD with intermittent steering codes. These codes set on startup maybe 1 out of every 20 startups. Only after engine starting the buzzer begins and steering lights illuminate. Generally speaking no codes are set and machine operates well( operates well even with the codes). One thing we have noticed is that on startup the secondary steer pump runs for a few seconds most of the time but not all the time. Is it normal for it to come on upon the machine being started? We have checked pressure as the service manual shows this code setting at over 1050 psi but we do not go over this pressure at least while the gauges are connected and we are watching! - the code will not replicate for us while we are watching the pressures. Pressure fluctuate from about 525 PSI to 750PSI constantly fluctuating unless we very carefully center the steering joystick(very very particularly; tapping with finger). Any input would be appreciated.