Just had my car serviced but the check engine soon lite is still on, how do I get it off?

SERVICE ENGINE SOON Indicator
The SERVICE ENGINE SOON indicator receives its signal from the PCM over the SCP network. If the instrument cluster does not receive a message from the PCM within 5 seconds, the instrument cluster illuminates the SERVICE ENGINE SOON indicator and log a diagnostic trouble code (DTC).
The blub is probably burnt out , pull the instrument cluster an replace the blub .

Not related. The service engine soon lite is operated by the speedometer, so it's just coincidence that it came on soon after the water pump repair.

does it make any irregular sounds when its running.

service engine light------scan for codes
brake light and antilock brake light ----abs problem scan for codes
change oil light ----- change oil and reset system light

When the Service engine soon, ABS and TRAC lights are turned on at the same time the computer control units for the engine and the ABS/TRAC systems has sensed a fault in the electronic controls of the engine and/or the emission system and the ABS and Traction Control system (part of the ABS system). When this happens you will seldom feel the car engine run any different or the car drive any different. There are about 200 possible faults that turn the Check Engine light on, the fault in your car is likely a part called the VSS sensor to know for sure what the problem is you must have the system tested; Kragen and Autozone parts stores do this testing for free

It's a "service reminder" based on your current mileage (odometer) Check your owners manual vs your odometer mileage and you'll see what's required for service.

the ground comes from the ecm. either the ground wire is open or ecm is not sending the signal

Your vehicle’s computer system has self-testing capability. When the computer senses that there is a problem with one of the components or sensors it stores the correspondent trouble code(s) in its memory and lights up the "Check Engine" or "Service Engine Soon" light to tell you that there is a problem and you should have the car diagnosed and repaired. First step is to find out what code turned the light on.

go back & sleep with the mechanic, that always works for my sister.

the service engine soon lite comes on due to an input sensor to your vehicles computer that has gone out of its parameters. this lite does not come on due to mileage. the computer needs to be scanned for code #'s in order to diagnose correctly. autozone will scan codes for free. if you get me the code #, ill try to assist further, otherwise you may want to see your local garage.