Warning Lights, Triangle ! and VSC. Transmission Problems?

You need to give more information for the experienced Prius members here to give you help.

1. Prius model/year (2006 in profile)
2. Miles on the odometer
3. Tranny maintenance to date
4. Other maintenance: 12v battery, ...

How far are you from southern Indiana? Steve at AutoBeYours.com is a great, independent Prius repair facility.

JeffD

 

My guess is that you should replace your 12v battery. Is it still the original?

 

Install a new 12V battery, and have the inverter cooling pump recall performed if it has not been done already. If it has been done, check it for proper operation, i.e. turbulence in the reservoir when in Ig-On or Ready.

 

I don't know where to jump in here, but this sucks...the tranny and the inverter both die at the same time! Total cost to repair: $11,000. No way I can afford that so I have to scrap the car and buy something else...

2006 Prius Gen II Millennium SilverPackage #3 (no frills)
164,000 miles
TLC from day one; all service current

Waiting for the dealer to tell me what the codes were; all fine until I was pulling onto the highway, steady acceleration, and then *SNAP* (that's what it felt like - when a rubber band breaks) RED Triangle, Engine SVC lites and a whirring high pitched whine from the engine. Coasted home (lucky) could not go faster than 18MPH...

A true summer bummer...

 

Hi Jacob,

DTC P0AA6 and P3009 both are reporting a high voltage fault isolation problem. P0AA6 is reported by the hybrid vehicle ECU while P3009 is reported by the air conditioner ECU.

P0AA6 means that the high voltage fault could be anywhere in the high voltage path from the traction battery to the inverter, to the transaxle and AC compressor. A three digit info code potentially may focus the problem to a narrower area. P3009 seems to be focusing on the AC compressor.

Can you ask for the three-digit info codes associated with both DTC?

As you have learned, the car will not start until you have cleared the DTC. However once you have cleared the DTC the car can be driven with no driveability symptoms. The only issue is that it is not tremendously safe to be driving the car with one side of the high voltage line touching body ground. If the other side is shorted (via collision accident for example) then you may have a big safety problem.

 

desertron, what you have described may actually be an HV battery failure. Please do post the codes. It may be one of the three unholy triad repairs: transaxle, inverter, or battery, but only 1. Whoever quoted $11,000 is stupid.

 

Okay Folks, lets all get our heads together on this issue.
I have experienced a rash of calls this week with the same P0AA6/ 526 and p0aa6/613 codes.

first of all, Change the transmission fluid, and inspect the resolver plug on the transmission for corrosion. while your at it check the other plug next to the resolver too.

I suggest dividing the problem into two halves starting with the A/C compressor
http://www.autobeyours.com/gifs/Tech%20Tips%20Prius/P0AA6%20526.jpg
Unplug the A/C compressor, then drive the prius to determine if the P0AA6 code returns.
if not..you know the problem is not the transmission

also, for those of you who are stalled with a prius that will not go into READY mode.

try "rebooting " by unplugging the 12 volt battery for a minute then reconnecting it.
no tools are required to try this and it has helped many a stranded prius owner in the past.
first look at these photos

then

then

 

The A/C compressor plug is under the plastic cover next to the inverter.

do this with the car OFF!


this procedure allows for determining if P0AA6 codes are within the AC system or elsewhere.


if the problems go away, then the isolation fault was due to a bad compressor, or the wrong oil being introduced into the A/C system.

this means flushing the system or in some cases replacing lines, condensor, compressor, and even the evaporator within the dash.
reminder.. never allow someone to charge your prius A/C with a machine that could have the wrong oil in it.

 

526 doesn't really help to narrow the problem down. However 613 does point to the inverter or transaxle.

The repair manual recommends that the tech disconnect the cables running from the inverter to the two MGs, then measure resistance of each of the six terminals leading to the MGs; to ground using a megger. (If the current leak is bad enough, a regular ohmmeter might be able to measure a resistance value less than infinity.) You might ask your dealer if the tech followed that procedure to identify the transaxle as the problem.

I agree that since it is easy to unplug the compressor and DTC P3009 was logged, this should be tried first.

 

Jacob,

First, "Woody" is Steve at AutoBeYours.com in southern Indiana. If after you do the diagnostics and it seems that a major item (HV Battery, Tranny, ... ) needs repair, get your Prius to him to do the job. The 3-4 hour drive from Ohio is worth it (There is a Super8 motel that is a 25 minute walk from his site, I've done that walk to have him get my Prius going). Patrick is a well known Prius DIY Guru so his suggestions are to be followed as well.

Second, your 12v battery looks weak so replace it. It should not drop below 12v after resting. the higher voltage 13.6-13.8 is seen when the Prius charging system is active, It says little about the condition of the 12v battery.

There are two good choices:

1. The OE battery from the dealer (Steve also stocks them) which is an Absorbed Glass Mat (AGM), lead acid battery that has a safety vent tube. Toyota dealers often overcharge for one. It should be less than $200 installed (Steve will do it for less)
2. An Optima Yellow-Top size 51 spiral cell battery. It is a somewhat more robust battery that fits, is also an AGM, and has provisions for a vent tube. You do need to adapt both the vent tube and battery cables to make it work. A kit to do this is available from:
   Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10
   With or without the Optima battery

Replacing the 12v battery is due even though it may not help with the codes, but it could. Good luck.

JeffD

 

Because the 12volt battery is the cheapest part to replace, by all means replace it.
they usually only last a few years, at worst you are buying one a few months early.

now, assuming you have eliminated that as a problem...lets look at the other components in the trouble area ( refer to the black and white photo of the wiring diagram above in this thread)
and lets also look at the simple solutions

it has been my experience that the resolver plug may develop corrosion inside.
replacing it with a new one is fairly easy and while your at it replace the transmission fluid with 4 quarts of WS fluid.

my next post will have photos of the resolver plug.

 

+1, take it to Steve, he probably has a salvage tranny that he can stuff in there and get you going again for a small fraction of a dealership charge for new. This is not a problem with the 12V imho.

 

P0AA6 526 & 613 Warning Lights, Triangle ! and VSC. Transmission Problems?

I found this Service Bulletin, if you do indeed have a bad tranny, then perhaps it may be covered under warranty.


for those of you who are still diagnosing... refer to the following photos.

It helps to get under the car. these photos are taken while standing under the front.


there are three plugs... I suggest checking all of them.
I have never seen corrosion except on the front ones.




I hope this helps.

next we will eliminate the HV battery by replacement.

 

Good, although probably not the culprit, I encourage disconnecting anything that could be affecting our results.
be sure to remove any wires connected the stock OEM battery pack.
in the case of P0AA6 trouble codes we are seeking ground faults.