My 2001 Volvo XC70 is constantly sending me all kinds of messages. I take it to my Volvo guy and he checks it, everything the computer says is wrong, says the computer is going to need replacement. Can I clear those codes at home, until I can save enough money for yet another expensive Volvo repair?

the cpu and engine management in cars is being constantly checked the same as your pc. It there are sensors that go outside set parameters ie temp speed crank timing the computer see these as possible engine failures and shuts down before major damage can be done. In you case if the vehicle runs as it should then the fault may have been simply a computer glitch ( same as your pc) that was corrected by the cpu on restarting. Be aware for a while of any unusual occurrences and have them checked out immediately.

Wiring, schematic, electrical diagrams, fuse diag, error codes, torque settings etc are basic contents of these online books they have here on this website www.reliable-store.com I have attached. Must check it out

"position light" is a rear parking light which has failed or become unseated. Sometimes you can knock on the tail light housing and they will come back on, but they burn out shortly after regardless.

These and the low beam headlamps fail very frequently on these cars so you should become familiar with the replacement procedures.

Check the online manual:

https://www.customers.volvocars.com/owners/docs/2004/2004_XC70/04xc70_08a.htm#pg122

Your owners manual should give you directions for resetting the message.

Well this can be caused by the thermostat being stuck open. The coolant temp will not come up to expected temp. It can also be caused by the fan being stuck on. Run the car and see if the fan stays on. If the fan is not stuck on it may well be the t-stat and replacing that should cause the check engine light to go off after a drive cycle.

remove the batter cable for a while and replace it back ( negtive cable)

Check two items, chassey grounds by battery, transmission and starter. Also, check to make sure the alternator is providing enough voltage, should be around 14 amps. Had a similar problem with my 2002 XC70, replacing the alternator fixed it! I used the Car Talk website to find a good local mechanic vs. the stealer.

If you have SRS and "brake failure" it should be taken to a dealer. a shadetree mechanic will screw more up than he will fix in this case. trust me on this! you will pay a price, but will save you more $ and less headache in the longrun.

Try downloading from volvo website. you should be able to do that.

Sounds like you put the wrong kind of fluid in there.

Also, NEVER list your email address in a public forum. That's the quickest way to get spam known to man.