Check Engine Light - 93 525i (E34)

[frodo1028]

I just bought a used 525i with the check engine light on. The engine seems to run fine but I live in California and the car cannot be registered without passing a smog test. However, I am told it won't pass smog as long as the check engine light is on.

My question is, will the check engine light go off automatically if the problem is fixed or does the system have to be reset by some mean. I was thinking maybe changing the plugs and doing a tuneup might do the trick without having to go to the dealer.

Any advice would be welcome.

Thanks

[darkhorse737]

get it scanned so you know what the problem is. That is the sane way to diagnose probs instead of blindly changing this and that as you go...

[frodo1028]

I just received the Bentley repair manual in the mail and it describes in detail how to retrieve and clear the "check engine" codes on page 100-8 through 100-10. It also gives a detailed list of what the codes are. Looks like the manual will be well worth the money.

Thanks

[pinnaclebass]

yes do gas pedal test to see ECU codes and diagnose problem that way. most likely on for a reason.

[p1zz4guy]

buy a code reader !!! it pays for it self after like two uses

[Bimmer M.D.]

listen to all the posts. get it scanned. It may be worth it to buy your own scanner. The pedal trick is also good to do, because it can read codes that the scanner cannot, because the check engine light does not always come on with thrown codes.