2003 Jeep Liberty engine light on

The computer did not say a relay was defective. No fault code in any computer ever says a part is defective or needs to be replaced. It only indicates the circuit or system that needs further diagnosis, or the unacceptable operating condition. When a sensor or other part IS referenced in a fault code, that part is actually the cause of that code about half of the time. First you have to rule out wiring and connector problems. Reading a fault code is only the first step in diagnosing the cause of a problem.

The first thing to do is to have the code(s) read in the Engine Computer. It's hard to know if the problem that was detected is related to the electronic stability program. Logic would say they're not related since they occurred two weeks apart, but we won't know for sure until we know what the codes are.

You also didn't say which relay was referred to, if it was replaced, or if replacing it solved a problem.