I have a 2002 Xterra SE SC with 90,000 miles on it with no past history of problems. Last night in the middle of a 30 minute drive, the SES light came on solid. Checked gas cap, wiring, air hoses, but found nothing. The only thing out of the ordinary was the coolant tank was empty. I have noticed a little drip here and there over the past few months, but nothing major. I plan a timing kit replacement in the spring, so figured it could wait till then. The big question is whether low coolant will cause the light, and if so, will it go out on its own since I have refilled the tank? The X runs fine...for now!
got access to a code reader? maybe one at an auto parts store. once you get the codes someone can help a bit more. I don't know a whole lot- learning as I go. But I doubt an empty coolant reservoir [I assume you mean the overflow tank] would trigger a code. But I'd watch the coolant level. IF it's going down quickly or you've got WHITE smoke out the tailpipe that's a whole other bowl of wax- possible head gasket. Some first ideas to think about, hope it helps a bit
I went to have codes read at Autozone last night. First one was P0328 knock sensor (KS) circuit high input, and the second one was P1491 vacuum cut valve bypass valve. I should mention that my dad and i replaced the plugs a month ago with some degree of dificulty. The SES light just came on a few days ago, so I can't imagine that has anything to do with the current situation. The truck still starts and runs just fine. Thanks again for any help.
important one is the vacuum one. the knock sensor seems to be common and not much problem [usually safe to ignore in non supercharged truck]. look in form "repair questions". there's two sticky there- one on the knock sensor and the other a link to the factory manuals. look up the section on engine control. there's a list of codes and how to figure out what's up and how to fix it. good place to start
I bought some Lucus Oil octane booster and filled up with premium fuel since I had been using 87 for some time. After about a week, the light went out, so I have no idea why the vacuum error code cleared itself. Now I just hope it doesn't come back for a long, long, time.