2003 With P3120 Transaxle Code

Yes, it sounds like the transaxle needs to be replaced based upon the DTC and your driveability symptoms. Can you locate an independent willing to install a salvage unit?

 

I agree with Patrick. Funny, some of the symptoms sound a little like Orangeboy's old transaxle that lost the oil. As a quick test, see if there is any transaxle oil in the pan. If it is the same problem, loss of transaxle oil, flat towing may not be an option.

Bad noises and a lot of resistance if you try to manually push the car? (Sorry, I don't know your snow conditions ... best done when dry.)

Which part of Indiana?

Want to swap the transaxle yourself or take Patrick's advice, find an independent mechanic to swap the unit?

FYI, you can probably get a good deal on a 2010 the end of this month.

Bob Wilson

 

Sorry to hear about your transaxle.

Were there any noises associated with the failure?

In neutral, if I pushed my car, the engine turned too so it kind of lurched along as the cylinders went thorough their cycles. Like push starting a manual. I think the gears had seized. I still have to find some time to take it apart and see the guts.

If you can find a good used replacement, $500-$1000 (carpart.com) It's just a standard in and out. Usually several hundred dollars. Any shop should be able to do it if they are not afraid of hybrids. Just tell them a few of non professionals have done it in their driveways and that should "appeal" to their mechanics egos.

That is if it is shot, but that description does not sound good.

Let us know how much they offer you, If you do decide to trade it in (and you don't mind). It would be interesting to know.

 

If you want to read the subcodes you are going to need the equivalent of the Toyota diagnostic laptop which costs $6K. I don't see that knowing the subcode will help you, as they all relate to some part of the transaxle and you are going to have to replace the entire transaxle anyway.

 

Kenopa where are you in relation to Scottsburg Indiana? Autobeyours specializes on the newer gen Prius but he may be able to help you in some way with this.

 

Autoenginuity is working on a gen 1 code reader apparently as we speak. They have a pc based one for 2004-2009 and I assume the 2010 is coming soon.

 

That is the standard error screen. Mine was exactly the same but my battery was fine and my steering was fine. Has anyone actually seen other two icons in red? I haven't.

Is the car idling smoothly? I have heard of one of the plug coils going bad and causing misfiring. Might cause a jerky motion and low power. Check for water in the spark plug holes. Water can collect there and drip down. That could also cause low power and a jerky engine.

Whether that can cause a transaxle failure code is anyone's guess. Some times the computer gets mixed up because of a low 12V battery.

The last independent mechanic to drive the car wrote "transmission wonky" How's that for a symptom description? It finally quit in the hands of the Toyota dealership who didn't bother to check the trans fluid level before taking it on a test drive.

 

Hummm, usually I try to visit the Georgetown KY plant but making a left turn at Louisville works for me. However, I am trying to visit Re-InVolt in NC next weekend. I'm me think about the logistics.

Somehow it sounds as if one leg is lost. If you take off the windshield wipers and rain shield, you can access the MG2 terminal block:


If you open it up, disconnect the inverter leads and then measure the resistance between the three legs of MG2. Internally, all three stator windings are tied together in a "Y" configuration. What we need is the resistance between all three legs looking for either an "open" or a "short".

That the car seems to move OK on ICE power suggests MG1 is probably OK. MG2 is the likely source of jerkiness when moving the car about on EV mode. But I would not rule out the inverter (a much more affordable part!)

With the inverter leads free, measure the inverter lead-to-lead resistance and for good measure, reverse the measurement leads. If you have a manual resistance scale, use both the lowest and highest scale. Although it may seem silly, please minimize the potential for electrostatic discharge into the inverter leads (ESD wrist strap.)

I would also recommend unplugging, cleaning, and replugging in the MG1 and MG2 sensor interfaces. The reason is if any salt water ever gets there, a corroded connector could look exactly like a broken transaxle. There is another set in the car under the carpet of the sloping foot area where the hybrid vehicle ECU resides. Inspecting and reseating them is also probably a good idea.

These are the most extensive, not removing the transaxle, tests that can be done. Finding and fixing a dirty connector is a whole lot easier than replacing a transaxle. It sounds like the mechanicals are OK.

As for buying a 2010 Prius, it is a buyer's market. I would have no problem with buying either a new or used (non-crash) 2010 Prius. Given a choice, I would buy a used 2010 Prius with accident avoidance, automatic cruise control and lane assist in a hearbeat if you can get it closer to say $25k. New they were running over $32k.

We are keeping our 2003 Prius because it is paid-off and is a dandy commuting car. The 2010 handles errands, highway trips and bad weather driving.

Bob Wilson

 

You have my sympathy ... it is not a good place to be. If you do let the dealership take a look at it, feel free to suggests the tests I've proposed. There are no guarantees in life but these are fairly 'cheap' tests.

I agree that $1,500 is low and faced with a similar, low-ball dealer offer, $2,700 for our 2001 Echo, I found a private buyer at work for $3,000. I think three parties were happy.

If you decide to DIY (be sure and evaluate your time and tool costs.) What scanner are you using to read the codes?

Bob Wilson

 

A conventional ohmmeter is not sensitive enough to detect a short in these windings. And an open winding would prevent the vehicle from moving. So unless you have an ohmmeter that can measure in thousandths of an ohm, you may want to skip the tests.

 

Screen 1 would have also listed the three-digit information code. You need that.

Ignore C1259 for now. It's a companion code to P3120. Focus on P3120.

 

So you can't find any transmission shops in Indiana that are willing to install a salvage transaxle unit?

If you download the repair manual info from techinfo.toyota.com that would help to show the magnitude of the job.

 

Or look at Tomfreed and Orange4Boy's photos. It does require heavy lifting and/or careful attention to jacks, jackstands, e.t.c. The reason for using a transmission shop is they have the tools to handle the heavy lifting ... but then they may not pay attention to torque values . . . Mixed bag.

Bob Wilson