How do you get the service engine soon light to reset on a 1998 Pontiac grand prix gtp?

You can't reliably reset the "Service Engine Soon" (SES) light on a 1998 Pontiac Grand Prix GTP simply by pressing buttons or disconnecting the battery. The light illuminates because the car's onboard diagnostic system (OBD II) has detected a problem. Ignoring the light is not recommended.

Here's the proper procedure:

1. Identify the Problem: The SES light is a symptom, not the problem itself. You *must* determine what triggered the light. The cheapest and easiest way to do this is to get the diagnostic trouble codes (DTCs) read. You can do this in a few ways:

* Auto Parts Store: Most auto parts stores (like AutoZone, Advance Auto Parts, etc.) will scan your car's OBD II system for free. They'll tell you the codes, and often give you a possible explanation.

* OBD II Scanner: You can buy a relatively inexpensive OBD II code reader from an auto parts store or online. This allows you to read the codes yourself, whenever needed.

2. Repair the Problem: Once you know the DTCs, you need to find and fix the underlying problem. This might be something simple (like a loose gas cap) or something more complex requiring professional repair. Do not simply reset the light without fixing the issue; the problem will likely return.

3. Clear the Codes (After Repair): *Only after repairing the problem* should you attempt to clear the codes. There are a few ways to do this:

* OBD II Scanner: Most OBD II scanners have a function to clear the diagnostic trouble codes. This is the recommended method.

* Disconnecting the Battery (Less Reliable): As a last resort, you can disconnect the negative battery terminal for about 10-15 minutes. This *may* clear the codes, but it's not guaranteed, and it can cause other issues like resetting your radio presets.

Important Considerations:

* Ignoring the SES light is risky. Driving with a malfunctioning component can lead to further damage, reduced fuel economy, and even safety hazards.

* A simple code reader is often sufficient. You don't need an expensive professional-grade scanner unless you're planning on doing extensive diagnostics yourself.

* Professional Diagnosis: If you're not comfortable diagnosing and repairing the problem yourself, take your car to a qualified mechanic.

In short, resetting the light is the final step, not the first. Focus on finding and fixing the problem that caused the light to illuminate.