Hey guys, so I’ve had my 02 for about 2 years now. Since I purchased it, it occasionally wouldn’t start. It would crank but not turn over. I would take the keys out, wait a couple of minutes, try again and it would start. Now recently the problem has been occurring more and more frequently, up to the point where it happens almost every time I try to start the vehicle.
I noticed that when inserting the key, if the immobilizer indicator light (green key) on the dash illuminates for a couple of seconds, as it should, then the car WILL start. Now if I insert the key and the immobilizer light does not illuminate at all, the car will crank but will NOT turn over. This has led me to believe that my problem lies within the immobilizer system or possibly the ecu.
I have already replaced the immobilizer unit attached to the ignition cylinder, and the corresponding fuses. The problem still persists
A few things that might be worth mentioning: occasionally while driving the car will lose power and sort of sputter, or it might just stall out. After a few minutes it will start up again. This happens rarely but it does happen. Another thing I noticed is that when inserting the key, IF the Immobilizer indicator does NOT illuminate, neither does the check engine light. When the immobilizer light DOES illuminate so will the check engine light. All other dash lights seem to work fine.
Any ideas of what might be the problem or how to diagnose it? Much appreciated!

I considered trying a new key but concluded that the key isn’t the problem. if it was a bad key, the immobilizer indicator should light up and continue blinking. In my case it didn’t light up at all.

I believe I’ve found the problem though. This morning the immobilizer and check engine lights didn’t come on. I tried to plug in an obd scanner to see if I can get a connection. When I accidentally nudged the fuel pump relay, the immobilizer and check engine lights came on briefly. So I pressed the egnition start button and it started. I tried this a few more times with the same result. I ordered a new fuel pump relay and I’ll be swapping it out later and taking it for a test run. I’ll post the results after I drive it around for a week or two