My ABS, TCS and Brake dash warning lights frequently stay on when I start the van. If they come on, they stay on for the duration of the drive. This can happen for days on end, and then they’ll magically not stay on for some time. Someone told me they thought it might be related to the alternator, but I had the alternator checked, and the dealer said it was fine (but they had no other clue as to what is causing my problem).
Have you checked the brake fluid level?
Also could be as simple as a bad ground. Use a test light to check the hot lead and the ground.
I don’t know who said it is related to the alternator, but don’t ask them for any more advice.
As noted above, check the brake fluid level.
After that you are probably looking at a problem with one or more of your wheel speed sensors - that is what ABS (which is brakes) and TCS have in common.
When the ABS/TCS/Brake light is lit you do not have ABS brakes or traction control working. You have brakes, just not the ABS action if you should hit some water, snow, or gravel.
Have you had your brake fluid changed? This is an every 3 years maintenance item with Hondas that have ABS brakes. It should have been changed at least twice by now. If never changed you should get it done. It could just be low fluid in brake reservoir, but it can be a much more significant and costly problem too.
You can drive the vehicle but you are less safe than when the ABS brakes are operating properly.