What might cause my 2004 Acura MDX check engine light to come on and vtm 4?

The "VTM4" light refers to the "Variable Torque Management 4WD System" and could be triggered by many different errors aqlong with the "check engine" warning. Under inflated tires or problems in the rear differential can activate the VTM4 warning and AWD will automatically be suspended to prevent damage to the vehicle or its transmission. At speeds over 18 mph the VTM4 restrictions will be temporarily suspended, but it is not advised to drive with this light illuminated. Sometimes, the knock sensor has become faulty located near the intake manifold. Several owners have reported this problem due to animals nesting in that area. The light can also be related to emission errors and replacing the EGR valve is usually required under these circumstances.