I have 1999 silverado check engine light stays on

Does the code reader power up ? Does a message no communication show on the screen ? Is there B+ voltage at pin 16 in the DLC ? If all that is good try a auto parts store ,they check codes for free .

The engine light stays on because the computer has detected a fault code, when disconnecting the battery the memory is cleared but the fault code will eventually be set in the computer again until the problem is fixed, since there are many reasons for the check engine light to come on it is necessary to connect the vehicle to a diagnostic computer that can read the codes, this can be done at most repair shops, the dealer or some autoparts stores.

What is the fuel presure? on a vortech engine the presure needs to maintain 60-66 pounds. It is possible that the fuel filter is restricting the flow of gas or could also be a weak pump... just a another thing to check... hope it helps.

In most cases the light will go out by itself once the problem is resolved that made the light illuminate. You can RESET the light by removing and re-installing the fuse(s) marked as ECM in the fuse panel or by disconnecting the battery for several seconds.

If the light continues to illuminate, You will need to extract the computer codes from the computer via the factory specifications to see what code(s) are being stored in the computer.

NOTE: Disconnecting the battery will cause the engine to run a little erratic until you drive it for several miles so the computer can re-learn it's proper settings.

How to Reset Service Light
Chevrolet Suburban 2000-01
GMC Yukon XL, Chevrolet Silverado,GMC Trucks Sierra 1999-00
Turn the ignition key to the RUN position. Fully push and release the accelerator pedal 3 times within 5 seconds. If the CHANGE OIL SOON light flashes 2 times, the system is reset. However, if the light comes on and stays on for 5 seconds, the system did not reset. Repeat the procedure if the system does not reset.

Let us know (remember rated this help). Good luck.

I'ts a chevy V8 350 engine. lol

Disconnecting the battery might reset the check engine light on some cars. However, instead of doing so, I'd recommend to bring your car to a dealer or a mechanic for proper diagnostic, and here is why:
- not all cars will clear the code after disconnecting the battery
- often, the problem may be actually covered by the warranty and repaired free of charge by your dealer. For example, if you have the code P0420 - Catalyst System Efficiency Below Threshold it's very possible that your catalytic converter is still covered by the original emission warranty and might be replaced free of charge (would cost you close to $1000 otherwise).
- some problems, if not repaired in time may cause a serious damage and more costly repair.
- disconnecting the battery will cause basic settings of the vehicle's computer to be erased (e.g. idle settings, fuel trim settings, transmission shift points, etc.)
- the Readiness code will be erased, which may prevent your car from completing an emissions test. (Readiness code is an indication that certain emission control components of your car have been self-tested)
- the radio, if code-protected, may be locked after disconnecting the battery
- the "check engine" light will come back anyway if the problem still persists. Thank you.

YOU MUST GET THE COMPUTER CODES FIRST TO SEE WHAT THE AREA TOO LOOK FOR COULD BE SIMPLE LIKE A VACUME HOSE/ INTAKE LEAK/ BAD MASS AIR METER . LOTS OF STUFF GO TO PARTS HOUSE MOST OF THEM OFFER FREE SCANS THEN REPOST YOUR CODES THEN WE CAN HELP

disconnect the negative cable but leave the positive cable on
if this does not work then it will have to be scanned

This image applies to engines with A.I.R. system

This image is for vehicles without A.I.R.

Hope this helps.

hi, ok I'm sure you tried alot of solutions, I think the ECU has governed the engine must have sensed a previous problem or its just a malfunction from a sensor, important sensor to check is the 'engine knock sensor' try disconnecting and reconnecting it or test with multimeter and compare all readings with a new engine knock sensor or disconnect and reconnect battery, the other way might be to reset the engine managment system, this however I dont know but your dealer can do this for you.