I was getting tired of paying into the Volvo Service Manager Retirement fund. After paying $108.00 and $75.00 for diagnostic checks (within two weeks), only to have them tell me that it was a loose gas cap. I had to take matters into my own hands.

WARNING - WARNING - Before you proceed, make sure that you have your Volvo Radio Security Code, it should be 4 digits.

Now, locate a wrench or pliers and disconnect your battery cables for 5 minutes.

Make sure your gas cap is on very tight.

Next, reconnect your battery, power up your radio and punch in your security code using the numbered radio buttons, set your clock, program your radio stations.

Start your car, the check engine light should be off. You have just reset the on-board computer. If not you have a bigger problem.

So far mine is working fine, over 150 miles and still out.

If the gas cap is the cause of a CEL, it will go out by itself after a week or so. Brought mine into the dealer the first time this happened and this is what he told me. Had it happen again and just ignored the light for a week and, indeed, it went away. For the most part, as long as the gas cap is secured after filling up each time AND you don't run the car extremely low on fuel, the light won't come on. The 2 times it came on for me both involved running the tank down to less than 2 gallons.

Done this before. It's gonna come back if there is really a problem. I finally got a OBDII reader to eliminate the guessing game.
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JJ

For under $180 you could purchase an OBDII code reader that will read and codes and reset CE light. By disconnecting the battery you have not erased the code from memory. I am not sure why your CE light is not on, maybe for certain codes it works. In any case having a code reader in your tool arsenal seems necessary these days as the car mechanics (dealers and independents alike) can take advantage of the CE light being on, especially at annual inspection time. Now, there are many codes that are Volvo proprietary and will not show up on the generic OBDII reader, but I have succeeded in extinguishing the CE light with one of those code readers even as it told me no codes have been read. So, IMO, $180 is not a huge price to pay.

Good luck.
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Vladimir. 1998 S70. Base, 5-speed manual.

Where can i buy the OBDII code reader. I am assuming it is a hand held device that can tell me exactly what is wrong. I bought a 98 S70 and the CE light came on driving home from the dealership (bummer) and the car was really missing. Anyways driving after a while the missing stopped but the CE light stayed on. I let the car sit for 4 days started it up and no CE light or missing.
I would like to know what went wrong??? The car is parked in storage until my lease on my Maxima runs up in August. I would like to start "playing" with it to see what is wrong?
Will this OBDII work with my 96 850 GLT?
Thanks for your help!!!