'99 V70 210K miles. Cold weather. Drove short distance and all lights flashing as engine stopped. Few key turns to restart. Stopped again, then started okay but ran rough for few seconds. Is this an ECT problem? Engine light itself does not come on.

thanks Doug

 

ECT as in the coolant temp sensor? My first thought is, the lights all came on because the engine stalled. Running rough on the start up could be caused by remnant issues from the stall. I wouldn't suspect the ECT unless you have repeated cold (or warm) start or running issues. easy enough to test however - simply unplug its connector (off to the side of the thermostat dome) and measure resistance. generally the resistance of the thermistor is high when cold (ie 3K ohms or more below room temp) and low when warm (ie 300 ohms or less near operating temp 180F+). if the ECT fails via an open circuit, it will be high all the time, or via a short you'd see it low all the time.

 

Thanks so much for the details! Will check it. Had timing belt replaced awhile back, so I know it's not that.
Could it be fuel sensor?

 

If the engine stalls you get bulb check mode. They always do that. That's not helpful, but I thought I would just clear up that mystery. I agree with mt6127. I don't personally keep any ECT volvos at my house, so I can't help on that part of it.

 

Thanks to all: It was the darn negative battery cable connection at the engine block. Replaced that and Voila!! Appreciate this forum. Doug