My 02 Altima cranks over but doent fire. Is there a possibility that the computer chip in the key is causing this problem? I do not have the master key, just a spare. The dealer has the master key. Ive heard that this can cause starting troubles. Please let me know if you can help.

Do you know how to test automotive electrical circuits using a DVOM - digital volt ohmmeter ? Reading a wiring diagram so you know what all is involved in making the starter work ? If not ,your best bet take it to a qualified repair shop . We don't just replace parts .
https://www.youtube.com/watch?v=0mKrx-fMi_8

Lots of things can result in a no spark situation. Have you checked for injector pulse at the injectors as well? This can help in the diagnostics. Possible crank sensor causing the no start ( common ) on these engines. However, there can be a lot more things to cause this problem as well. Wiring/relay/computer/fuse to name a few

camshaft sensor, crank shaft sensor. possibiltys. do you have a computor chip on your key, if so do you have a secound key? it is possible the key chip failed, if equipet

Either the chip in the key has failed, or the sensor in the lock cylinder.
You can try a spare key to knock that off the list of possible causes.
Until the PASS module sees the right chip in the key, the car will not crank or start.

could put a resistor in the line at the switch,but without the old chip,can't tell how much resistance,maybe customer has a spare key?

possibly the fuel pump. fuel running thru the pump is what keeps the pump cool. if it runs out of gas it will get too hot and fry the pump. running one out of fuel causes a lot of pumps to go bad. id start by checking fuel pressure

The crank sensor is only a reference and shouldn't cause it not to start. I would look elsewere for your problem ie camshaft position sensor which is built into the distributor. This is amore likely cause of your no start condition.

Hello . So your transponder key is broken ? If the transponder is missing or broken then the car will not start. The transponder is like a fuse in the key that must send a sig to the ecu and back to the ign system to allow vehical to run. Quinn , Arizona

It is the security chips in the keys. Has this car been wrecked? Was this car made in Mexico? GM had the bright Idea of creating a security system that would do exactly this, I know on cars made in Mexico (like the HHR) You can reset the power and get the key back out, but vehicle will have to be reprogrammed with the master key. This involves turning the key from off to run position without ever going past run (i.e. start position) leave key in this position for 30 minutes. Turn key back to off for 30 seconds then back to run for 30 minutes. repeat this step three times. the last time, after 3rd 30 minute period, turn key off for 30 seconds and then try to crank. Please note this only works if the original master key is being used. You can then reprogram the second key following a similar sequence, only master key that is working has to be inserted to let alarm system know that vehicle is not being stolen only that you are trying to reprogram a key. If original master key is not being used then vehicle has to be taken to the GM dealership to program keys and possible key module replacement.

The key, regardless of whether or not it has a chip in it has to be programmed at the dealer. They have to hook the computer to the vehicle to perform this. When you go you will need to take any and all keys that you have for the vehicle. Once you initiate the reprogramming procedure you must do all keys at the same time.