Hey Volvo people, I've got a few questions I hope you'll bare with me on. I'm quite knowledgeable about a few things but cars are not one of said things.

So, how do you get these codes that tell you whats wrong? I've heard of people going to Auto Zone, that they'll run tests and such for free. Problem is my Volvo doesn't feel like starting some days (separate thread for that), so that may not be an option. When I get payed this Friday I'm going to buy a maintenance manual which should clue me into some things, as I've found looking under the hood is like trying to understand Japanese.

Another- I was driving on the highway yesterday and my Volvo shifted, hesitated, then started running loudly. The upward pointing arrow on the dash lit up. I know this has something to do with over drive. The engine was much more sensitive to how much I depressed the gas pedal and no amount of pushing the small button on the side of the shifter (automatic) did anything, the arrow remained lit.

Thanks for any help, I'm excited to start learning at least SOMETHING about cars. I feel dumb being 21 and only knowing how to check my oil level...

 

What year and make is your car?

Regarding the overdrive, I would first take a look at your overdrive relay. Check the threads in the forum hear. There are many write-ups on rhis issue (even an active one: OD/4th crazy problem). Some of these write-ups describe where to find your OD relay (depends on the make of your car) and how to fix/replace it.

 

Being able to check your oil takes you off of the noob club for sure. Anyways, defiantly get a repair manual like you said. I have a Haynes and Bentley book which are great and take a different approach to problems each. I don't like the idea of paying over $40 for each though, so if you can spare some time, look for a used one like me. One came with my 240 and the other I picked up among a floor mat, light bulbs, and some panels all for $5. Those books will tell you how to check you codes, but yeah, what do you have?

 

My bad, I have a 1988 240 DL. I just fired it up this morning after a no-start day yesterday. It ran a little rough and the idle wasn't as high as it usually is. It's normal to me but probably not "normal" at all, that the idle in park is higher than reverse, drive ect... Probably just burning off the gas from all the attempted starts yesterday. After attempting I could always smell unburnt gas. Regarding that problem I'm going to go ahead and replace the engine temp sensor since they're not too pricey and it wouldn't hurt to replace it anyway since I don't know if/when it has before. But finding it's locating under the hood will be interesting...gotta get that manual!!

 

The starting problem could be the crankshaft position sensor. If you get a manual look it up and it will tell you how to test it. My 740 was doing that it would start one day and then it wouldnt.

 

The codes you have heard about are for cars 1996 and newer, OBD 2 system.