Red brake light comes on, revving noise

How long have you owned this Prius?

Bob Wilson

 

Ok,

Let me suggest reading the "sticky" articles and evaluate your skill and resources. A 12 year old car is going to take a lot of extra maintenance. If you have to pay someone else, it can become pretty expensive. For a car as rare as the NHW11 model, parts are going to be a challenge.

If you are interested and committed, the NHW11 can be rewarding. But there is no 'free lunch.'

Bob Wilson

 

When you click on this link, you'll see the next level of this forum: Generation 1 Prius Discussion | PriusChat

At the top are three 'threads' discussing different aspects of the Prius. In particular, take a few minutes to read:
Who should and should NOT buy a 2001-03 Prius | PriusChat

Then use the 'search' function to lookup the error codes.

I'm not trying to kick sand or call your car ugly, just discuss the facts and data of what it means to own one of these cars. We're not going to ignore you and folks are willing to help you keep the car running. It is not trivial nor is it beyond the skills of ordinary technically skilled folks.

Bob Wilson

 

Hi Daniel,

You know what each code means, but we don't know what they are yet, because you haven't posted them; there might be some useful information there. [Edit: forgive me, I had actually missed where you posted them later.]

My next question would be, have you managed to identify the "whirring/revving" noise yet? Do you think it is actual revving of the ICE? (You could make that judgment by comparing the sound when you rev the ICE on purpose, or by plugging in a scan tool and watching the RPM when it happens. Is it similar to the sound your Prius used to make decelerating in B mode before this problem appeared?)

Under what driving circumstances does the sound occur?

-Chap

 

Hi Daniel,

No insult was intended. Just sometimes folks buy used NHW11 Prius with 'great expectations'. Owning these older cars works best if you are prepared to do as much self-maintenance as possible. At a minimum, getting a Prius-aware scanner so you can read out the current problem as they are worked.

There are hard limits on how much we can tell from lights and noises. You mentioned 'brake light' and we know there are reported problems with older NHW11s and the brake assembly. They can develop a leak that requires replacement of the whole assembly. When the electric pressure pump runs, it makes a faint sound disconnected from engine operation. However, whoever ran your codes did not report a brake error. Still, it is worthwhile to check the brake fluid.

I won't insult your intelligence about the other P-codes. However, a Prius-aware scanner would be able to read out the voltages of all 19 module pairs. If one is 1.2V lower than the rest, there is a failed module and the traction battery needs replace or repair.

The other thing a Prius-aware scanner can do is check temperatures of the motor-generators in transaxle, the other major risk.

GOOD LUCK!
Bob Wilson

 

Given that only DTC P3000, P3006, and P3015 were logged by your car, I would say that the driveability issues you noted can be attributed to the traction battery failure and after it is replaced, those issues should go away.

Several years ago, I also experienced failure of the traction battery in my 2001 which was replaced under warranty. The car was very difficult to drive to the dealership, 5 miles away. I don't remember whether the BRAKE light came on or not.

 

Hi Daniel,

If the battery ECU is detecting trouble with the battery while it is sourcing or sinking current, it might at any time decide to reduce the amount of current allowed. The HV ECU has to immediately compensate by commanding the engine control module to make up the difference. That can lead to sudden unexpected changes in ICE output. Once the current is reduced and the battery under less stress, its condition can seem better and the ECU allows more current again, with the result that the ICE sort of cyclically hunts between lower and higher output. During deceleration also, where regen braking can supply a large current to the battery, the current might have to be limited. The car has a couple tricks it can do with excess regen current: it can just do less regen and apply the conventional friction brakes harder, or it can dump excess regen power by spinning the ICE with fuel cut off (the B mode effect that feels and sounds like downshifting in a conventional car).

So yeah, most of what you're seeing does not seem inconsistent with a straightforward traction battery issue. The brake light doesn't surprise me (the brake ECU needs to know when there are limits to the regen capacity the HV ECU can promise, so they talk), but I'm a little surprised the codes you had read didn't include any for the brakes. Maybe if you get a scan tool and read again there will be more codes. C1259 at least is almost always there when the brake ECU has learned of a problem from the HV ECU.

As another real simple unrelated thing that could make the brake light come on, have you checked the level in the brake fluid reservoir? If the fluid level looks ok, have you checked the wiring and connection to the level float switch in the reservoir?

-Chap

 

That is one of the key items that alert you when you have a traction battery failure..Yes the brake light comes on and the whirring you hear is the battery fan in the back trying to cool a hot battery module.. The Ice also revvs very fast.. If you replace the battery pack that should take care of those issues..

 

Hi Daniel,
My problem is exactly same. First I had those check engine light etc. on. Dealership scanned and got similar codes. Then they suggested equalisation and I got that done. Not any help. Now I am waiting for the new hybrid battery to come... may be next week. In the meantime I have that emergency brake light bothering me... exactly as you had. Checked the brake fluid levels... they are fine. I will wait for the new battery and then let you know.
Meanwhile please let me know how you are doing. Thanks.

 

I got new battery installed last week at Toyota dealer. It is running fine now.