The mode shifts are shifts from 2HI to 4HI and 4HI to 2HI. A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the driver can shift into 4HI merely by pressing the 4HI select switch button. The 4HI button will blink status whenever a 2HI or 4HI shift is initiated and will continue to blink until the TCCM completes the shift. After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI.

There is a difference between when the TCCM sends voltage signals in order to engage a four wheel drive shift and when the vehicle is truly in four wheel drive. The transfer case can be shifted into 4HI and the front axle may not be engaged.

The driver can shift from 4HI back to 2HI by pressing the 2HI select switch button. The 2HI select switch button blinks until the shift to 2HI is complete. The 2HI select switch button will remain on once the shift is mechanically complete.