John Shulse

We have a 300 Mercedes in 07 Tour Master by Gulfstream. Love our motor home but we suddenly had engine light check, shut engine down. All gauges were good checked oil,tran,radiator all seemed OK. The engine ran fine but would stay on. Had Mobil diesel mechanic come, pressure checked the radiator inspected engine.When you slow down will go off then come back on as you apply accelerator. Where is the code check(It a freight liner chassis)? Any help John Shulse jshulse1938@gmail.com