When you drive a car in Illinois, whether you have a valid license or not, you give consent to any law enforcement officer who suspects you are under the influence to test your blood, breath, or urine for the presence of alcohol or controlled substances.  You still retain the right to refuse testing and you cannot be forced to submit.  But your decision to take a chemical test or not will have ramifications for your license.  The length of time your license will be suspended is indicated below:

First Offender:  Someone who has not had a D.U.I. disposition or statutory summary suspension in the last five years.
If you take a chemical test and it shows you have a blood alcohol concentration in excess of 0.08, or you have any amount of a controlled substance in you blood, you will be suspended for a period of six months.

If you refuse to take a chemical test you will be suspended for a period of twelve months.

Second Offender:  Someone who has had a D.U.I. disposition or statutory summary suspension in the last five years.
If you take a chemical test and it shows you have a blood alcohol concentration in excess of 0.08, or you have any amount of a controlled substance in you blood, you will be suspended for a period of twelve months.

if you refuse to take a chemical test you will be suspended for a period of three years.

The statutory summary suspension will go into effect forty-seven days after your arrest for driving under the influence.  The suspension will remain in effect regardless of whether you win the D.U.I. or not.  In other words the statutory summary suspension is separate from the D.U.I. criminal charge.  You may challenge the suspension with a petition to rescind, which is discussed below.