Red warning light came on and went away

I believe the codes are still logged even if the triangle has gone away. If you can, get the dealer to tell you both the DTC code and Toyota's internal information code (INF code). Some DTCs have multiple INF codes which give a better indication of the problem.

 

Is the rear hatch properly latched/closed? It can remain closed but not be properly latched, and if in "D" it will light the light if the hatch "bounces" causing the interior lights to flicker.

 

Check if the inverter coolant pump is still running by looking in the reservoir for waves.

 

So your not sure as of yet whether it was the Red Warning Triangle or Headlight Icon?

Fortunately or Unfortunately...it's probably a situation where it's either nothing...and it won't happen again...or it's a problem that will get worse and then there won't be any question as to obtaining a code or what light is on...

Let's hope for the former...

Slightly off topic, I appologize, but I recently bought a new car. The first I've had in a while. (not a Prius). I also unfortunately became involved in a slight rear end collision...very minor bumper damage.

Given the newness of the vehicle I was very concerned about any damage. So I call the dealership and ask if they could check the vehicle out. The Service advisor asks me if I have any warning or dash lights illuminated. When I say I don't, he's like they can't do anything for the vehicle and he "knows" sight unseen the vehicle is fine. Huh? So mechanics are now so computer reliant that they can't look at a vehicle or know what to do unless they have a dash light and a code? I literally had to beg them to just do a visual inspection. Begrudgingly they eventually humored me by at least pretending to take it in and look at it.

Have things changed that much? Is that just the way it is with new car dealership service departments now? Seems like they don't want to do anything to your car, or don't know how to do anything for your car unless you have a clear code and a light on your dash.

 

"Actually, they don't want to do anything on your car unless you pay them for it".--Yeah, I agree...but I was so freaked out after being hit that I was willing to pay them and I got the feeling I could of told them it was smoking, misfiring, and blood was mysteriously dripping from the headliner and they would responded by telling me I didn't have a problem unless a light came on on my dash...it's probably just the way it is today...I just need to adapt.

 

In my 09, an open rear hatch does not activate the master alert.

 

It depends on the sequence of the "interior light circuit" being energized. If you energize it -before- you put the car in "P" it will light it up. That is, while "driving" (even if you are stopped with your foot on the brake). In this case you also get a very "loud" message on the MFD, telling you to not leave the car in "N" etc (even though for me it's still in "D" - I open the drivers door to align the car in the garage to a mark on the wall).

 

It's supposed to drip blood from the headliner.

OP, take your car to one of the auto parts stores that will read & clear codes for free & tell us what they found. Next, buy a ScanGauge so you can do this yourself & get loads of useful information. You only have to use it to read & clear codes a couple of times for it to pay for itself. Just saving the annoyance of driving to the dealer to have the car checked makes it worth every penny to me.

 

FYI guys - if all you need is a code pulled, you can go to Autozone and have them use their scanner to get it for free. No need to deal with Toyota dealer BS.

 

My intermittent master warning light was actually for low engine oil level. No errror code was generated.

 

Yes, there is no engine ECU DTC for low oil pressure or oil level.

My question is, why was the engine oil level low? Was this due to a servicing error; or an oil leak; or the engine consuming oil?

It's important for you to know the answer to this question and take steps to prevent a repeat occurrence (such as periodically checking the oil dipstick level when refueling.) It'll be pretty costly for you to replace an engine that has been damaged due to lack of lubrication.