Audio question re: 2002 MCS

We just bought a 2002 ML55 and both my wife and I LOVE our new addition! I am still learning the ins and outs of the Modular Control System and was wondering if there is any way to get lower than 87.9FM? We use 87.7FM to listen to our local ABC TV network and this is the first car radio I have seen that does not have a way to get to this frequency. Any help will be greatly appreciated!!!!!