A tiny Brake light issue.

We don't yet know whether this is a tiny brake light issue or a bigger brake light issue - it would be best to have the diagnostic codes read using a Prius-aware code scanner. If you don't have access to one (you can find options searching this forum), it is probably worth asking the dealer to read the codes and give you a printout of all the codes (and any "INF" subcodes) read. If you post those here, there will probably be some suggestions forthcoming.

If it's really hard to find a scanner or get to a dealer, you can get the brake ECU to blink its codes out on the dash. Search this forum for messages containing some combination of { tc cg blink code } and you'll see how to do it. Several of the computers in the car will start blinking different lights on the dash, and you especially want to write down the codes blinking on the ABS light.

That might reveal something useful. The trouble is, I'm thinking it might only give whatever blink code translates to C1259, which would only mean the really important codes are in the HV ECU, which doesn't have a blinkenlight so it has to be read with a scanner. We won't know until you try though.

Good luck,
-Chap

 

Sounds like it could be a bad battery module...

 

I have had two Generation 1 Prius with the same problem you describe. "I pull over and do a shut down, then everything is peachy." Usually it happens on a freeway, and when it happens, the car won't go over 25 mph. The dealer seems to not know about this issue. But, it'a happened with TWO different Prius cars that I have owned. (I returned the first car to where I bought it.) So... did you ever get the thing figured out????

 

I had a brand new HV battery installed in November of 2012 (still under warranty) by the dealer at a cost of $3,800.00. When this issue came up, I took it to a different dealer and they said it was the HV battery. So, I showed them the Invoice where I paid $3,800.00 for the new HV battery, and they said, "Let me do more tests." After more tests, they came back and said it was the transaxel (and they wanted $4500.00 to fix it.) I opted not to have them do the work... and they still charged me $350.00 to run the tests. Currently I am driving it with the issue. I just don't see why it would drive perfectly... and then *poof* it revs up, no power, and I have to turn it off and turn it on, and then it works perfectly again. Seems like a sensor, and not the transaxel. Your opinion?

 

Hi folks,

This is new but sounds a little like the 'battery balance' cycle I've heard about but not experienced. Are any of you able to instrument the car:

• scangauge II - with XGAUGEs for codes and traction battery metrics
• miniVCI and laptop - to launch when the problem happens

There are half a dozen control computers that operate this car and without some metrics from the computers. In particular the hybrid vehicle, battery, and possibly the engine controller, I don't have anything.

Bob Wilson

 

It doesn't sound like any normal battery balance cycle to me. I think I've experienced such a cycle, but (a) it's rare, I think I've noticed it maybe 2 or 3 times in 5 years, and (b) it's designed to be inconspicuous, if you're paying attention you'll notice the ICE picking up a bigger share of the load more of the time, and with a ScanGauge you'll see the SoC going far above where it normally stops, but the car goes where you point it and drives normally the whole time.

A car that is switching suddenly to a mode with no more than 25 MPH travel is going into limp-home mode because of a problem. To amplify what Bob said: it makes no sense, no sense at all, to try to guess why without the info from the computers.

-Chap

 

The other thing you could do is give us your location and we may be able to hook you up with a prius garage tech or individual who would help you with it..

 

Bob and Chap,
Doesnt this sound like an inv coolant pump problem? Those symptoms are what I know to be classic inv coolant pump indicators.

Here's my logic:
The car drives fine because most of the time, the inverter never heats up outside of the safe zone (due to short trips or cool weather). Every so often (ie highway driving) the inv heats up and shuts down to protect itself (limiting the car to 25mph). A reset of the ignition resets the circuit and the inverter has cooled to an acceptable temp. The driver drives more carefully and the inverter stays within safe limits. I'd be willing to bet its the inv coolant pump causing the problem.

 

As others have said, get the car scanned! If you don't want to pay the dealer and no Hybrid shop near you, try AutoZone, Oreilly, etc. These stores will scan the codes FOR FREE, they won't have a 100% Prius aware scanner, but the codes they retrieve may give you some helpful data to share here.