Didn't know it could do that

jeffcoslacker · #1 10-01-2004, 07:25 AM

OBD II never ceases to amaze me. The other day, I went out early in the morning, to do my obligatory early a.m. weekend thrashing of some unsuspecting back road, and the MIL was on. For the last few years it has come on every few months, and I found out that a good 90 mph+ romp for a few miles will make it go out again. Never bothered to pull the code, not that concerned about it. But I did the "blow out", and it was still on. Disappointed, thinking I have some new glitch to chase, I headed home to investigate. On the way, I stopped to get gas. My fuel cap was missing. Some SOB took it in the night, I know, because I had washed the car the night before, and I always wash inside the fuel door (yes, I'm nuts) and the cap was there then. Didn't know it could sense that. Got a new cap, and the light is gone. Amazing.

cadgear · #2 10-01-2004, 08:57 AM

Its part of the EVAP system, I believe. The cap keeps a certian vacuum in the tank, and a sensor...well, senses the pressure in there. If its missing, then it'll mess the good ol' boys up. ODB2 is pretty awesome. I think we get to play with the CAN stuff in ASEP class.

tblake · #3 10-02-2004, 04:34 PM

yeah, I has heading out of town one time last summer, and my check engine light came on, and I damn near shit my pants right there. I dont like seeing that light, ever. So, I pulled into my mechanics shop. Very very nice honest guy. He pulled out an obdII scanner, puched a few buttons, looked at me, "Its your EVAP system", he walks to the back, tightens the gas cap, starts the car, light goes off. He saved me a lot of headaches.

gapboi210 · #4 10-02-2004, 04:45 PM

The same thing caused that light to come on an '01 Cavalier that I was driving. Even thought it was just the cap, dealership had to reset the light. Got smart, found another way to charge you. (Even though I didn't pay it) they said it normally would cost about $65.00 because even after you tighten the cap, it stores the code.