Engine/Transmission (1998.5 - 2002) check engine light

[dzollner]

I have a 98. 5 24v auto and the check engine light has been going on for a couple days and then it goes off. The last time it was on for two days straight so I called the dealer to bring it in I would have to wait until the next day. The next day when I was on my way in the light went off and the dealer could not find any codes. It is completely stock except for an air filter. When the light comes on the truck seems to run no different and starts good. The light was on today again and I finally realized that it only comes on when the air temp is cold (under 20-25 degrees). Anyone have any ideas what might be wrong?

 

[RFirpo]

I got a check engine light while driving around in Iowa while visiting my son. The truck had never seen cold weather but it was in the high 20's over night. I found a code P00071 and P1603. Apparent battery temperature sensor problem. The check engine light kept coming on. I disconnected the batteries for 30 minutes and the light has not come back on. The truck performed well on my trip back over the Rocky Mountains and Utah, Highways 80, 76,70 and l5 over the course of 25 hrs driving time in two days. Iowa to Southern California.