Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
L2 & L4 keep the transmission from shifting above the respective gear, so when you use e.g. L2 it will keep 2nd gear instead of shifting to third.These are good if you have to tow heavy things, going uphills or if you want to utilize the engine brake.
L2 position is also good for taking off in slippery conditions, as it will reduce the torque to the drive wheels and lessen the possibility of spinning the tires.