Suddenly my abs and powersteering stopped working after replacing a fuse on my lexus is 250

look at the wiring at the rear end and check for broken wires , broken wires at the connectors , loose harness connections ,dirty connections , power at the harness plug at the ABS and ECM unit..

this will most likely to be a signal from one of the ABS sensors not in the correct range , it could just be a worn wire , and the signal to the ECU isn't making the correct adjustment/reading , will need to be checked by a auto electrician as they will know the correct procedure to trace the fault as you could spend hours searching and not find anything, do the brakes feel like they are operating correctly? if not i'd have this seen to as soon as possible

Sounds like a major fuse blown.
Any wiring disconnected or stripped near the pump ?
Have you checked the major fuses around the battery and underhood fuse box ?

I have this exact same problem with my 2006 IS 250 as well. It happened just last week and it was sudden; I pulled out of a parking lot and noticed the steering wheel was very hard to turn. I wonder if this is going to end up being another recall for toyota.

My wife has the Lexus IS250 with Navigation and just this morning she tells me she wanted to raise the AC from Low to higher position, but that nothing on the Navigation screen is working. I tried what David mentions above, but the only fuse that had 15A on it was in xlnt condition. Any other suggestions? Dealer talks like $1500 and the system has always been mediocre at best. Thanks for any help.

Hopefully all you blew was some fuses. Need to check all fuses under dash & in relay/fuse box underhood. Easiest way, hook up test light to ground & test across all fuses. If blown 1 side of fuse will get power,but not the other side.

My 2007 Lexus IS250 is dead, hooked up a charger. Charger keeps shutting off. Triple checked the cables, + - correct, still shuts off charger?

that problem is from brake servo,you have to replace or change it

You need to check timing belt. could have broke belt.Also you should look at water pump if you replace belt.It is driven by the t-belt.

It's the medium sized black box located under the drivers seat