My son's 98 sunfire 2.2L has a passlock system (no chip in the key)
We have started having problems with it when he got it in June 2013.
Some days it would work fine, others the theft light will blink 6 times then go steady and just stay that way.
Sometimes disconnecting the negative terminal from the battery for 30 min or so then performing the 10 min relearn will allow the car to start.
We've replaced the ignition cylinder at least 6 times (both aftermarket, new factory and junkyard), replaced the instrument cluster with a junk yard part. All of these replacements have worked for a brief period of time then right back to ole 6 blinks and no start...
The only "semi-consistent" in this is that it seems to happen more when it is cold or wet out. But it sometimes works then. Also, any time my son has no option but for his car to work, that is almost ALWAYS a given that it won't work.
ANY advice would be GREATLY appreciated!