Originally Posted by joshkramsey
My overdrive light started flashing so I checked it with my SCT tuner. I have p0603,p0705,p1000.
P0705 is the transmission range sensor circuit malfunction (PRNDL Input) the switch thats connected to your shifter. this may be the cause of your overdrive problem due to you PCM needs to know what gear your in to know whether or not to activate overdrive
The P0603 is a Very common code It simply means that at some time in the recent past the PCM went unpowered. The batteries were disconnected, the PCM or it's fuse unplugged,
P1000 is no issue just means OBD-II monitoring is not complete but its a diesel so you dont need the emission monitors