I have a 1999 Trooper with the TOD system. The check light flashes and the ABS light comes on at the same time

It sounds like you have a bad abs sensor. If you don't notice any problems when braking then you should be able to ignore it. All brake systems are designed to work even if the abs system stops. Mine quit working a long time ago and it never mattered unless I slammed on the brakes when it was wet. If you live somewhere that gets snow then you definitely need to get it fixed.

Thanks for the answer. I should have given a little more information. The check light on the TOD is intermittent and the abs light comes on with it just occasionally. I've seen something about a speed sensor and I believe there is both a front and rear one of those. I also am getting a po446 check engine light and I'm wondering if that could be a charcoal canister issue. Thanks for any answers.

OK so first the abs system has a sensor on each wheel. As far as I know the TOD system works separately from the abs system. If you have no diagnostic equipment then just check the wiring around the crossmember that runs under the transfer near the transfer case. One time I found mine came a little too close to the exhaust and melted some of the insulation. Also make sure that transfer case fluid is topped off with dexron 3 while you're down there. As for that 446 code I had that one on my scanner for years until I figured out what the problem was. There is a small pipe that runs from the back of the throttle body to the egr vlave. You will need to remove the throttle body and the egr to clean it. The best way to get in there is with a rifle cleaning rod with a .22 Cal brush on the end. I didn't have one but a coat hanger worked instead. The one side of the pipe faces the back of the throttle body and the other points up at the bottom of the egr. I used some seafoam penetrating spray (like wd40 but stonger) and used the coat hanger with it to open up the tube. You'll know when it's opened up when you get the spray coming from the back all the way to the front. You can see other guys doing the same thing to their 3.2l Rodeos on youtube. Be sure to get gaskets for the throttle body and egr before you start and give both a good cleaning before you start.