Downshift problem in 2005 Camry XLE V6

you may have a short circuit in the system seek auto electriction

Check your light switch which is the main one,after that check whether you do have any reset procedure through your ECU.

Sounds like you might have a v6 engine. The only solution to this one is to replace the transmission. Google the car there is nothing but problems with the v6 transmissions if left unfixed it will leave u stranded be carefull

It is hard to be certain, but your brake discs may have become warped. This causes a pulsating feeling in the pedal. They can be replaced fairly easily.

You really haven't given us a huge lot to go on there, but I would start by looking at the shock absorber mountings in the trunk. It's possible that the rubber mounts are loose or worn and the shocks are rattling in their mounts as you go over bumps.

ABS kicks in. It's normal on a rough road with hard , sudden braking. On regular road it may kick in too with real hard stop.

Need to know which model sedan you have, CE, LE, XLE, and which motor you have 2.2 4 cyl or 3.0 V6, also email address to send diagram/instructions to replace your water pump, no they are pretty easy to replace.

Is it coming from the driver side, passenger side, front or rear of the engine? It could be a cam or crank seal if it is coming from the passenger side behind the plastic timing cover.

When was the last time it was tuned up? Since you did not mention any "check Engine" light coming on, I assume that it is off. What I would do is check the plugs, replace them if worn, replace the plug wires if they are older than 5 years; check/replace the air filter. Not much else to do/check until you have the engine in a good state of tune; BTW, if you change the plugs, get the new ones at a Toyota dealer. I have a Camry V6, and when I put non-Toyota plugs in it, it ran worse. Toyota platinums made a 100% difference.