[bk3104]

My wife has a '98 V70 AWD. We've got just over 60K on the clock right now. The check engine light has come on twice in the past month. The first time, our shop checked the codes which told him that the gas cap had been loose. He cleared the codes, we tightened the gas cap and had happy motoring for a few weeks. My wife then fills up and leaves the gas cap off, driving away from the station. Yep, the check engine light comes back on. She gets a replacement cap, puts it on and asks the dealer if they could check and clear the codes for her. They didn't have time and told her that the check engine light should clear itself by 100 miles if the condition that prompted the light to come on was no longer happening. This is the first I've heard of this and wanted to know from everyone if that was possible? We've driven close to 300 miles since the light came on. The assumption is that it is on for the gas cap issue again, but naturally we don't know the answer for that unless we have it checked. Can the check engine light extinguish itself?

 

[Kobejitsu_X81]

Normally, any Volvo mechanic can manually turn off the Check Engine Light. I had a similar problem with the light on my 98 S70. Did you happen to get a 60K tune up? timing belt, oil change, and all?

 

[bk3104]

Oh, I know any mechanic can turn the light off. It was just interesting that he said it should go off by itself, which it hasn't. We didn't do the 60K service. We're gonna bring it in around 65K or so and combine the 60K with the serpentine belt service as well.

quote:

Originally posted by Kobejitsu_X81:
Normally, any Volvo mechanic can manually turn off the Check Engine Light. I had a similar problem with the light on my 98 S70. Did you happen to get a 60K tune up? timing belt, oil change, and all?

 

[rothe]

Yes, the check engine light can go out automatically under certain circumstances. To my recollection, it depends on the code that turned it on in the first place -- some codes will reset automatically, such as a the one for a loose gas cap or, as I found out recently, one code that related to a faulty Mass Air Flow sensor; other codes are more permanent, and must be reset with either the dealer's computer or any generic OBDII tester. In the case of my intermittent and recurring MAF sensor codes, the code would clear itself out of the computer after "3 consecutive key cycles involving 20 minutes of driving or more." In other words, a whole week of short hops to the grocery store might not clear out one of these codes.

If you've satisfied the driving requirements and the code hasn't cleared out of the computer yet, then it's not likely to be the gas cap -- unless, perhaps, your "replacement gas cap" doesn't fit properly. Is it a Volvo gas cap?

 

[bk3104]

Yes, it's a Volvo gas cap. My wife picked it up at the dealer. I borrowed a cable froma friend of mine and have loaded the obd-2 software on my laptop. I'm going to plug in to her car later and see what codes it spits out to me.

quote:

Originally posted by rothe:
Yes, the check engine light can go out automatically under certain circumstances. To my recollection, it depends on the code that turned it on in the first place -- some codes will reset automatically, such as a the one for a loose gas cap or, as I found out recently, one code that related to a faulty Mass Air Flow sensor; other codes are more permanent, and must be reset with either the dealer's computer or any generic OBDII tester. In the case of my intermittent and recurring MAF sensor codes, the code would clear itself out of the computer after "3 consecutive key cycles involving 20 minutes of driving or more." In other words, a whole week of short hops to the grocery store might not clear out one of these codes.

If you've satisfied the driving requirements and the code hasn't cleared out of the computer yet, then it's not likely to be the gas cap -- unless, perhaps, your "replacement gas cap" doesn't fit properly. Is it a Volvo gas cap?