Funny thing, I had my husband test my battery and alternater the other day. And I guess he had to unplug the batter to accomplish this, but it hasn't seemed to mess up any since then. Could that be because some cable or wire was lose and now its not? I've kinda always thought I might have some wiring problem somewhere, just for the fact that things keep popping up or warning lights come on and go off. Also, my door locks sometimes lock or unlock on their own. I just went to the antenna ring because someone had suggested it a while back. But I'm very appreciative and open for suggestions.

 

I took my 2000 C70 Conv. turbo (aka Money Pit) to volvo for a hard start issue with the same exact issue. They suggested to change the ect sensor and the thermostat. If that didn't work, they suggested the MAF sensor replacement.

 

If the MAF is shot, you will find a code displayed. By the way, CRC sells a MAF spray cleaner that works quite well and is something you should incorporate in your annual maintenance program which includes a brake fluid flush.

r.

 

Well, similar problem (intermittent failure to start) with my 2004 XC70. So, we replaced the (original!) 12V battery and the mechanic said to use my other key. (He opines that the old keys get a lot of wear and do not initiate reliable contact). We shall see.

 

Well, I'm jumping into the 'won't start' department. This morning my wife was heading to work and while the engine cranked, it wouldn't fire. It's an '05 XC70 with 106k on the odometer. We bought her used at 96k. The battery connections are clean, the Volvo brand battery shows 12.5 volts, though I don't know it's age, sure is clean though. I've read all the related posts I could find and joined this forum today. Pulled the column covers and used dielectric grease on the plug pins...tried both keys, cycled the locks...etc. The prior owned had about 4k of modules replaced. The check engine light came on a few months back and the dealer checked it out but found nothing. Last month the 'brake failure' message came on while my wife was driving the car, but after sitting for a half hour while I drove to meet her, it went back off leaving the check engine light once again. One of our customers drive an '02 XC w/225k and told me that his check engine light has been for nearly ten years. Since the car runs great, except for this, I'll pick up a new antenna ring, and try that. I'm thinking this could also be a connection due to temp changes as the first couple of things occurred on really hot days, and then the last couple of days it rained here.

 

Picked up the new antenna ring. Daubed a bit of dielectric grease on the pins, installed it. Car fired and ran roughly for app three seconds. Twice. Then back to cranking nicely but no fire.

 

Rode over to O'Reiley's and on the advice of a buddy, bought a Diagnostic tool ( INNOVA 3100 abs.) $129.00 plus tax with Veteran's discount. Got home, read instructions, scratched head. Found connector port through this site. Tried to start car & still no go. Plugged in tool, turned on ignition, tool read that it could not find computer. Had protocol # at bottom of screen and 11.6 volts at the battery, likely from me trying to start yesterday. I pressed a button (likely the DTC erase) by mistake and screen cleared. Nuts. Shut off ignition and disconnected tool to figure things out. Tried to start just in case the Gods were smiling on me. Car immediately started up, ran until I shut her down. I waited a minute and she fired right up again. I hate it when this happens because I have no idea of what I did. To be continued.

 

I always check for codes. No codes, disconnect battery to reset ECM. Start & idle vehicle for 15 minutes to let ECM re-learn engine management. Drive for 15 minutes to complete learning sequence. Battery readings below 13.5 volts tells you the battery is tired & wearing out. Summer time might be OK. Winter no way, cold starting problems will occur !! Clean tight terminals a must. 45 years of driving experience Montreal to Southern Calif. living. Also 9 winters in Japan. Aviation electrical engineer. Aviation computer programmer and repair!

 

I have the 2001 C70 convertible, I have the same issue of not wanting to start. I had assumed that it was due to the vehicle not being on level ground. The car seems to want to taunt my wife more than myself. I noticed also that it will do it when the gas tank is below 1/4 full. I will look into the key issue, take the battery cables off and on, bang on the steering column, curse the car, then maybe wash it and put it up for sale or trade....will keep you posted.