1. Get the Diagnostic Trouble Codes (DTCs):
* OBD-II Scanner: The most important step is to get the DTCs stored in your car's computer. You can do this using an OBD-II scanner, which are relatively inexpensive and available at most auto parts stores. The scanner will read the codes, which are usually a series of numbers and letters. These codes give you a much better idea of what the problem might be.
* Auto Parts Store: Many auto parts stores will read the codes for free. Take your car there, and they can tell you the codes.
2. Common Causes (Based on "Won't Start" and "SES Light"):
Once you have the DTCs, you'll have a much clearer picture. However, some common problems that can cause both a no-start condition and the SES light include:
* Camshaft Position Sensor (CMP) or Crankshaft Position Sensor (CKP): These sensors tell the engine's computer where the crankshaft and camshaft are in their rotation. A faulty sensor can prevent the engine from starting.
* Mass Airflow Sensor (MAF): This sensor measures the amount of air entering the engine. A faulty MAF sensor can cause a lean or rich condition, preventing the engine from starting or running properly.
* Throttle Position Sensor (TPS): This sensor tells the computer the throttle position. A faulty TPS can cause starting problems.
* Ignition System Problems: This could include issues with the ignition coil, spark plugs, wires, or the ignition control module. A weak spark won't ignite the fuel.
* Fuel System Problems: Problems with the fuel pump, fuel filter, fuel injectors, or fuel pressure regulator can prevent fuel from reaching the engine.
* Security System Issues: If your car has a security system, a malfunction could prevent starting.
* Battery/Alternator: A weak battery or failing alternator can also prevent a car from starting. Check the battery voltage.
3. Troubleshooting Steps (If you don't have a scanner yet):
While getting the codes is the best approach, here are a few basic checks you can do:
* Battery: Check the battery terminals for corrosion and make sure the battery is properly connected. Test the battery voltage with a multimeter.
* Fuel: Can you hear the fuel pump prime when you turn the key to the "on" position (but don't crank)? A lack of fuel pump priming suggests a problem in the fuel system.
* Fuses: Check the fuses related to the ignition system.
4. Seeking Professional Help:
If you're not comfortable working on your car yourself, or if the problem persists after checking the basics, take your Pontiac Grand Am to a qualified mechanic. They have the tools and expertise to diagnose the issue accurately and repair it.
Remember safety first! If you're unsure about any of these steps, it's best to leave it to a professional. Improperly working on your car can lead to injury or further damage.
