Check engine light but no OBD2 codes?

hollyrk · Post by **hollyrk** » 27 May 2010, 19:06

I think I might just have a horror story on my hands, but I'm crossing my fingers that it's not.

I bought a 2001 Volvo S80 2.09 (USA) used yesterday. It has just shy of 95k miles on it, all work and maintenance up to date by the local dealer with records to prove it. Took it to an independent Volvo specialist mechanic who said all was well prior to purchase.

Driving it home from work today, it threw a check engine light. There is no message in the message box. It seems to be running fine, no issues I can see or tell.

Ran the car over to Autozone to run the OB2 codes - no code pops up. Tried O'Reilly to see if their code reader said differently - same thing, no codes. Dealer I bought it from used (Honda, not Volvo) has offered to run the codes tomorrow when they open, but I'm thinking they'll get the same thing with a generic code reader. And OF COURSE, we're rolling up on a 3 day weekend and I'm scared to drive it with a light on just in case.

I tried to reset the computer with a solution Dr. Google gave me (holding the keys in position, holding down the trip meter til something beeped as described here on this forum). No dice, didn't clear it. I don't know if that's actually how to attempt to clear it in this model, so please enlighten me if I'm doing something wrong. I was hoping maybe I hadn't tightened the gas cap enough or something equally easy, so I redid all that and still, check engine light is there.

Any ideas to help calm me? I'm terrified of the thought of a surprise $3k repair bill a day after purchase. Any ideas what it could mean if the car isn't throwing a code at all?

Thanks in advance for any help you've got. This is the first car I've ever bought on my own - I've driven the bug I got when I was 16 for the past decade. Now I'm feeling a little stupid and scared.

jbrown122 · Post by **jbrown122** » 28 May 2010, 05:06

It could be a probelm that has nothing to do with the engine/transmission. There are tons of computers in that car and generic code readers wont pick up any codes from. So, your problem is probably not urgent. The procedure you used to reset the light was actually for the service light.
You could unhook the negative terminal on the battery, leave it for a few minutes. Put the key in to position II, and hook the terminal back up, the light should be gone.
Good luck

hollyrk · Post by **hollyrk** » 28 May 2010, 13:28

Thank you for the help!
Drove around last night putting the car through its paces - drove fine at high and low speeds, curves, hills, everything. I know I rescrewed the gas cap at one point and felt disheartened when the light didn't go away on restart. I'm now thinking that may have been the culprit since the light went off about 20 miles into the ride and hasn't come on since. I guess it just needed to run through a drive cycle before it would clear the light.

In related news, my heart is out of my throat now.

Post by **theWIFES_S70** » 12 Oct 2015, 07:21

Hey everyone, I have the same thing going on with my wife's, late model, 1998, S70. I have a code reader that's not picking up any codes, but when I turn the car on, there's a CEL. However, it does go away rather quickly (sometimes within 5 mins of driving). Is this something to worry about? Would you all suggest getting a "beefier" code reader? Thanks!

Marco

superglide9375 · Post by **superglide9375** » 24 Jun 2018, 16:46

ty brown 122 this method worked for me