I have read alot of people's comments with this same problem. The car brakes but the ABS system is not working. I am taking in for the diagnostics at Toyota . I will post what codes they come up with as this seems to help people out. I am pretty sure the car is going to need a new skid control module ( the computer) but it is possible that it may be ABS relay #1. I can't see the dealer telling me this but have seen that be the problem on one guys car. 12v battery is new, Hybrid system is working fine sounds like a nice aquarium and is flowing good so no overheating there. Pump was replaced a while ago at the dealer. All fuses are good. So lets see what the dealer says and I will follow up with the information.
99% of the clients I've had with this issue is the aux battery. New battery ...problem goes away. Once a client came in with a new battery he installed. I could't clear the abs vsc lights. Started troubleshooting and finally noticed he didn't plug back his ABS power module after replacing the battery. Lights cleared right up.
I believe I plugged it back in but will check again. Everything is plugged in. I guess lets see what they say?
Check and make sure your abs relays are pushed all the way in. Located under the hood is the fuse box.
This was my first guess was a relay. One guy posted that he spent $650 at Toyota and they found a short between the two relays. He replaced Relay 1 and it fixed the problem. I am going to try this after I get the car from Toyota today. I am going to let them diagnose it. I have to have a recall done anyway so I am going to pay them for and hour to see what they say. I just got the car back from Toyota. It is believed that the dying 12v battery caused the problem. Although I replaced it they had to perform Linear Valve Offset Initialization and then the brakes went back to normal. It did pull one code C1247 Stroke sensor. Sensor was tested and within specs but may need to be replaced. Total cost at toyota $125 and $200 for the new battery. Check the 12v battery on the car display as I did and could save alot of headache.