When the light comes on it is telling you there is a problem in the system. Without knowing what code is setting this is tough to answer. Regular engine scanners can not get into the VTM-4 system. What year is the Pilot?Customer :2003. I will inspect all of the Trans connections ans see if I find anything loose. Is there any test I can do to verify the operation of the sensors and switchesSteve :I do know there is a temperature sensor in the rear differential. This could be the problem but I can not be sure unless I have the code that is setting off the light.Steve :I am not seeing any test for the sensor. I would think you could check it with an ohm meter but I have no specs. for it.