Won't start

start

#1

2003 GMC Sonoma V-6. Drove to McDonalds cut off went in came out and cranks won’t start.Plenty of gasoline. Any helpful thoughts?

Thanks

Joe D


#2

Check if the fuel pump runs for a second or two when the ignition is turned to the run position. If you don’t hear the fuel pump run, take a large rubber mallet and give the bottom of the gas tank a couple of good whacks. Now see if it starts.

Tester


#3

Check to see if you have spark at your plugs. Remove a plug wire from one of your plugs install a screw diver into boot and put the metal part of the screw driver about an 1/8" away from a good ground. Be carefull to be insulated ,such as a rubber glove, from the screw driver so you don’t get shocked! Have someone crank engine over. If you have a nice blue spark your ignition system is working.


#4

Look closely at your instrument pannel - do you see the word “security” illuminated and probably flashing? If so - it is likely that your Passlock system lost it’s mind and needs to “relearn” which is an easy procedure.

The passlock system is part of your ignition and keylock - it basically “learns your key” (it works whether you have one of those keys with a chip in it or not) If it doesn’t recognize your key it will cut off the fuel injectors. Your car may run for a short time but will soon stall and leave you crnking with no start.

Here is how to relearn your key.

Turn the ignition on, turn it to start the engine and then release (leaving ignition on)
Observe the security lamp illuminated - wait about 10 minutes until the security lamp goes off.
Turn the ignition off for 3 seconds.
Repeate the above 3 steps two more times - after the third “cycle” your key should be relearned and you should be able to start the vehicle.

This is a common problem in newer GM cars.