Please HELP: Acceleration issues, VSC, Check Engine, Red Triangle

A bad or failing HV battery. What was the replacement you put in less than a year ago? Toyota new?

 

These lights mean you have codes. If you do not see the codes the reader you are using is not up to the job.

 

If the problem is a poor connection at the 12 V battery, it is conceivable that the codes are erased when the car looses connection with the 12 V. Check that the connections are tight at the 12 V.

If that's not it, there is something awry. There should be other codes besides the one that the dealer found. What was it btw?

 

Try to find the codes from your invoice and post them here. If you can't find your invoice, go on Toyota owner's website site and see your vehicle service history. It should be there.

 

Hi @PairofJacks / OP,

I've had almost the exact same problem. We recently replaced the HV battery, dealer pulled codes and cleaned fan, then replaced fan, then we replaced the coolant flow control valve, but still having a flash of red triangle, only on acceleration.

What did the problem end up being? What fixed it?

 

Have you checked your oil level lately?

 

Did you ever get this figured out? I’m having the exact same problem with my 2006 Prius, the day after getting an oil change.

 

I took my Dad to the airport in his 2009 Prius. While driving it back to my home, I noticed it did not shift. The engine just continues to rev higher as I accelerate. Is this normal for this car? Is there only one gear? It seemed to be running at a high RPM but I could not find a tachometer. Thank you!

 

How many miles are on the car?

Technically, yes there is only one gear. The car has an electronically controlled continuously variable transmission, so it is one gear set, but, under computer control, it can set any gear ratio as required to match the power requirement requested by the go pedal. This is coined eCVT by Toyota and it is quite a different set up to the older conventional belts and pulleys type of CVT.

Yes, it is and at the same time no, it isn't. if there are warning lights on the dash, It sounds like something could have gone wrong in the hybrid system, maybe a fault has developed in the hybrid vehicle (HV) battery (this is the big 201 V DC battery behind the rear seat), as it should sound more like a normal automatic car.

Are there any lights on the dash (you don't say)? I am assuming there are, as you have tacked onto a thread that has lights on in the title. If there are lights on the dash, they indicate that there are diagnostic trouble codes (DTCs) to be read by a scanning tool. These could be set by one or more of the 11 - 14 electronic control units (ECUs), so the code reader needs to be more capable than a budget reader that only read the Engine Control Module (ECM) (called the Engine Electronic Control Unit (ECU) by Toyota) and maybe the ABS ECU.

Once you have the DTCs you will know what is wrong with your Dad's car. Again, once you have read the codes, you could try clearing them and see what codes come back and how quickly they do. What to do next depends on the DTCs you get.

I hope that helps as a launching pad.

 

The codes are extremely important. The main differences between Toyota dealership mechanic and non dealer mechanic is 1. access to an information and 2. experience in handling solutions.

My experience for dealership is that solution is less important than making money by replacing as many parts as possible. Dealership training typically follows the same doctrine as lawyers—billing is everything.

The code reader tablet that is $1200 plus the subscription fee annually or monthly allows any certified mechanic or intelligent, experienced individual to read the codes and find a solution.

My mechanic (non dealer) hooks up his tablet, reads code, resets Prius to zero codes, has me drive car until warning lights come back up (almost always less codes than reading #1) and then proceeds from there.