2003 Pontiac Grand Prix - Answered Questions & Fixed issues

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Somewhere a poor connection is the cause. The year model indicates that some miles might be on the car. Open the bonnet?hood and inspect for a bad joint or some wire that is rubbing against the body. I will buy some electrical switch cleaner and spray the connectors. Just remember to let the connection dry before trying again, you don't want to short and blow something.

You would need to buy a factory service manual for that blend door diagram. Try eBay for a used manual set.

The speed sensor wiring may be bad . The ECM/PCM can go bad and a used one can be found though some need reprogramming.

What is hesitating - the engine or the transmission? When starting the car and putting it in gear, if the transmission shifts immediately into first gear and then shifts smoothly from first to second gear, I doubt its a transmission problem. However, if that isn't the case, you will probably need a new or rebuilt transmission ($1500+). Engine hesitation can be due to a lot of things related to the fuel system that won't necessarily show up on a code reader - for example, dirty throttle body, fouled IAC (idle air control) motor, fouled EGR valve, etc.

sensor 2 is the oxygen sensor and is after the cat converter sensor 1 is a heated oxygen sensor and is in the exhaust manifold or before the cat converter two completely different sensors

Without amp rating on charger let's move on to other items to look at. Are the connections to battery tight and clean. Make sure you have cleaned both posts. Make sure there is no corrosion on cable ends. Also look at the wire that runs to ground , insure that is clean as well. Reconnect battery! Turn off all accessories (radio, heater, A/C). When you open doors does the dome light turn on. Does the dome light dim as you crank / click. Can the car be jump started? If yes then I would lean to a weak battery. Without test equipment ( voltmeter) tough to varify. You didn't explain why you replaced battery, but a purchased battery usually will normally be enough. Make sure the battery size (amp hours) is rated for your engine size. make sure wires to your starter are also corrosion free. A bad ground won't allow enough current flow giving you the click no crank. try turning the key on off rapidly thus making starter move slightly and if it starts you are probably in need of new starter. The starter relay is easy to replace and cheaper so you can start there.

You need to do a fault code test, any Autozone or Oreilly parts store will test it for free. DO NOT BUY ANY PARTS BASED ON WHAT A PARTS PERSON SUGGESTS, they are not trained technicians and will just cost you money and frustration.

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I DONT THINK SO

Usually a humming noise ( will get louder the faster you go ) is associated with a worn/bad wheel bearing. If the bearing is worn bad enough, it can also produce a wobble. Have the bearings checked on the side/wheel the problem is coming from

I always go to the auto wreckers - you should be able to pick the parts you need for really cheap.

Check the fuses first
Or could b the motors for your windows

are you talking brake modulator or transmission modulator?

Really sounds like someone or something has plugged up your fill pipe. Is there any chance someone has done this? For a fix, if you will look under the car, you will see a place where the metal fill pipe meets the metal extension coming up from the gas tank. Between them is a rubber hose with a metal clamp on each end. You could loosen those clamps and remove the rubber pipe, and then see if something is plugging that, and where. The gas tank is removable, but both that and the rubber hose will be a "big job'. God bless your efforts.

what about it?

Something is not telling the car your door is closed check the light switch make sure it's pushing In and properly and getting contact

Your AC drain is clogged. If you look near the floor under the dash on the passenger side you will find a small rubber hose that goes thru the floor board. Take the hose off and clean it out. You will find that it is clogged with dirt. Once it is cleaned out hook it back up under the dash. You will notice that if the car is running with the AC on, you will be able to see water dripping on the passenger side under the car that will mean you cleaned the hose out and it is working.

35psi.