I get 3 dash lights intermittently

Have you checked the oil level? Did you say you looked at the inverter pump and there's circulation when you remove the cap? Have you checked the coolant level in your radiator? Have you ever done a coolant change?

 

Welcome to PC.
Another thing to add to the above list is check the brake fluid level.

John (Britprius)

 

My guess is you are about 2 quarts low on oil. The 2 marks on the dipstick (low and between full mark) is 1.6 quarts. Most likely you are under the low mark on your oil (probably won't even see oil on the dipstick if your light turned on), making it about 2+ quarts low.

 

276,000 Miles!

Wow.

Those are mainly lights related to brakes, suspension, traction control. And you say they manifest in a speed related manner?

First rudimentary diagnosis, it doesn't hurt to check oil levels and battery charge.

If that isn't it, I'd suspect brakes or suspension.

 

If it is the OEM 12 V battery and you plan to keep it a while longer, you are on the edge of "normal" battery life......or a bit beyond.
I recommend changing it or at least having a load test done on it before you start changing out other parts.

 

As JC said check the oil before driving the car. This problem arises many times. owners do not check there oil, and just have it changed at the required interval. When it is changed they do not measure how much oil is drained, and this could be well short of the required amount. Eventually the engine uses enough oil to bring on the oil pressure light "usually when cornering or braking" real damage is being done when this occurs as the light is a no oil pressure light not a low oil level warning.

John (Britprius)

 

I have a similar problem as Jerry LaBant, I will check oil etc., mine started to occur after I had my 2008 133k mile Prius jumped by AAA. Dealer replaced my 12 volt but lights are still intermittent. I've driven 500 miles since. Other internet discussions seem to indicate this may happen after the battery has been jumped. Dealer has suggested a $1800 fix, I'm skeptical.

 

That being the case, I encourage you to catch up on any deferred maintenance. The engine and inverter coolants, engine iridium spark plugs, and transaxle ATF fluid would be on the top of the list to replace. Check the engine coolant pump for leaks around the pump bearing and if present, replace that now.

You dodged a bullet by checking the engine oil level when you did. Each time you had a warning light appear during cornering, engine oil pressure dropped to a dangerously low level, causing damage to your engine. I suggest that you need to check the engine oil level at least once per month when you refuel.

 

You might have to pull your spark plug ignition coils out again. Check for cracks around the rubber seals where it connects to the spark plug. There have been some reports of cracking in the rubber seal which causes misfiring. You would have to replace the bad ones.....if cost is not a factor, replace them all.

 

It's best you hook up your miniVCI and pull the codes. It'll take out the guess work. Did you change the coolant and purge all the air out of your system?

Things that are usually addressed here are

1. Air in system after coolant change
2. bad coils
3. bad injectors (this is more rare)

There was a member about a month ago that had a ignition coil problem. Car drove without issues but I believe there were warning lights on. Dealer diagnosed an engine problem that would require $4000 to fix. Ended up going to a rip off mechanic and changing the coils for $1500 (including the diagnostics).

You can try cleaning your throttle body, not sure if that'll do anything but it won't hurt.