Interesting development...
She gets below freezing, and she loses her mind!
Three mornings in the past week, it actually got down to freezing, or a hair below. CEL came on on the drive home that morning. Was notably rougher in lean burn. Otherwise not much out of the ordinary.
Code was P1607, iirc, indicating an ECM problem. Reset it. Drove it to work the next day, 5 degrees above and no problem. Temp drops down below freezing, even colder this time, and CEL comes on on the way home again, and the engine totally bucks (misfire) whenever I let it go in to lean burn. D'oh!
Same code. Reset.
Gave it a day plus the weekend off. Weather warms up a bit, no problem for the first few days. Then it drops below freezing again, and as soon as I start it...CEL. This time I reset it before driving home. It had a couple of minutes to warm up as I scraped the ice off. Checked all the engine sensor readings before I left, nothing out of the ordinary. Drove home with no problems.
Weather has stayed above freezing. Been just fine since.
So...she doesn't like getting cold. Wonder why? Moisture gotten in to the ECM? quite possibly. ECM ground acting up under specific circumstances? Perhaps. Haven't figure out which ground belongs to it, though. Battery voltage taking a nose dive in the cold? Pretty good possibility. Voltage dip might be serious enough to annoy the ECM before the DC-DC converter kicks in. Will have to monitor battery voltage when next it's below freezing.
It's a mystery! I love chasing quirks on vehicles that have had more time spent working on them than driving them!
