NEW (old) Prius - help me get it home!

Hi GW,

It sounds like the inverter is working since you are getting 13.8V when the car is READY, so that indeed is good news.

Did you download the procedure to purge air out of the inverter coolant loop? That procedure is very time consuming and you must continue to work at it, opening and closing the two bleed valves, until you can see the front of the inverter coolant reservoir contains a higher fluid level compared to the rear of the reservoir. That will demonstrate that fluid is flowing through the reservoir.

Since you "bench tested" the pump and found that it will pump water, then it probably is OK. As you said the old coolant was "thick", the car probably did not had the coolant replaced in the past.

The original inverter may have a clogged coolant passage. However since you replaced the inverter, hopefully the salvage inverter does not also have a clog within.

 

my short story:
- the original pump is broken after 3 month of my prius purchase. didn't found locally the original one, and we installed russian analog from russian car (80% classic prius owners do the same in russia with the prius pump problem). the guys who replace pump says: the reason of the broken pump - very old coolant that should be replaced! russian analog is still with my prius (it was very cheap ~$17 and match for replacement sharp), the only differences is it sound very high, so i can hear it when the engine is off.
- after replacement of coolant, it's level was ok, next day i found that there is not enought level coolant in reservoir. there was about 0.2 liter missing and i add it in. after that - cooland flow is disapeared. car was ON for about 30 minutes - no coolant flow. but after the driving for about 5 km - the coolant flow is appeas again and currently no problems with it.

 

I think that you should continue the procedure, running the pump 20-30 seconds at a time, as per the link that you found. No need to drain the coolant out and start over.

After you've done the procedure another 6-7 times, if you still hear air in the system and you don't see the step in the fluid at the reservoir, then drive the car around the block and see if that helps.

You can't declare victory until you do not hear air in the system, and you can see the fluid step in the reservoir. Otherwise the inverter may overheat and fail.

 

My experience also was that the symptoms could be most severe with the wheel lightly gripped or hands off. In a way, the car has been training me to be more consistent with a good two hand grip--and I really haven't noticed any jitter for a couple of months now. It may be that weather has some effect, or some dirty spot in the transducer got cleaner with normal use, but I have a pretty strong sense that my grip change contributed to the improvement.

I don't think that would appeal to me, just because of the effort involved in making the swap; I'd be pretty averse to the risk of having to do it again soon.

I did discover a remanufacturer though. I have not seen reports from anyone trying that rack, but galaxee reported good experiences with Cardone in general.

The information in the manuals suggests that the transducer is nothing more than a mechanically linked pair of variable resistors. The common opinion about the problem is that the contact area between the resistors and movable wipers gets noisy (because oxidized). I got weird readings trying to measure the resistance of mine, which could mean it is really something more complicated than just two pots--but could also mean it's just two pots with pretty bad oxidation. I haven't made any further effort to be sure.

If the two-oxidized-pots picture is correct, it might be possible to use a circuit idea I had a while back, to build a box that could attach at the ECU behind the glove box and condition the signal. If it turned out unable to make an already-bad rack usable again, it might still be able to greatly prolong the life of a new or remanufactured one. One of the objectives is to maintain a constant small "wetting current" across the pots' wipers, an established technique for keeping oxidation down. So far I have not tried this circuit, and nobody else on PC has critiqued on it, so it's just a raw idea at this point.

I haven't thought much recently about it, since I haven't been having the problem lately.

How did you make the homebrew vacuum refill? I've been wanting to brew one myself.

Regards,
-Chap

 

I guess you could just unplug the torque sensor at the ECU behind the glove box, and substitute 4 fixed resistors:

Code:

             Vref

             _|_
    750    _|   |_    750
         _|       |_
  VT1  _|           |_  VT2
        |_         _|
          |_     _|
     750    |_ _|    750
              |

             gnd

... run the ECU's zero-point calibration, and call it manual steering.
No assist, and probably no warning lights.

 

The plugs are custom so you'll need to do something special. I haven't done this, yet, but you could cut the wires and put in a small, standard connector for those signals. Then you can slip in a spoof circuit or resistor network of your own design.

Bob Wilson

 

The Electrical Wiring Diagram is your friend here; you can order the bound paper version from the Toyota MDC at 800 622 2033, or spend $10 for a one-day subscription to Toyota's Technical Information Service online and view the same thing as a bunch of PDFs. The bound copy's about $47 (which to me was a bargain compared to futzing with the braindamaged javascript at the TIS).

The 4 torque sensor wires do arrive at the ECU in a single dedicated 4-pole connector. The wiring diagram has a section at the back with connector part numbers, and your dealer can use the connector part number to look up the terminals that go in it. At the parts counter they will only sell "repair terminals" which have a few inches of random-colored wire precrimped to them, at about $6 a piece. Of course you can do a nicer looking job for less if you know somebody on the mechanical side of the dealership, who has the box of plain terminals, which they don't tell the parts people about; then you just crimp them yourself onto the wires of your choice.

For some reason the practice of having plain terminals for the dealer mechanics but not orderable as parts seems to be universal; it took me about 3 years of owning the previous Ford to get on the right side of a mechanic who would admit to knowing where the box was, and I'm still not there at the local Toyota dealer....

You could buy a housing and 4 terminals and make your own resistor network to simply plug in, or just buy the terminals and reuse the connector housing from your wiring harness, by releasing the 4 terminals in it and taping them.

-Chap

 

I actually just bought a used rack and pinion from Car-Part.com--Used Auto Parts Market and had an independent shop install it. Book time for that job is 4 hours, so take their rate and multiply it and you can figure out what that should run + a front end aligmnent. I found a used one for $350 and paid $360 for the install plus an alignment.

The dealer quoted me $2,100 for the job including a rack. ($1,200 at your local autoparts store).

dave

 

Don't forget to swap out that right tie rod. And as I said, the book rate is 4 hours for that job, and I think they had my car done including an alignment in 4 hours when they did it last week, so a competent shop can make some money off the job even if their rates are reasonable.

They offered a lifetime warranty on the rack for that price also? That was a great deal you got on it. My only fears with the used rack is that it was from a 2001, which was the year that they issued the extended warranty on, but I don't think you can go wrong with that price if it works, unfortunately the only was to find out if it does work is by installing it.

Keep us updated on the progress.

dave

 

Well, once we get past the necessary disclaimer that I Have Never Done This Myself And It Is Only What I Think Will Work....

Yes, 750 ohms. Don't worry about watts, the ECU supplies a regulated 5 volts here which will make a current around 7 milliamps; the smallest resistors you'll find will be 1/8 watt and you won't come near making those warm.

You probably know this, but the "square shape" in my drawing only represents the way to connect them electrically - the actual shape you end up with can be whatever compact arrangement you manage to origami them into. The resistor leads will be uninsulated, so once you've connected them you will want to insulate the whole schmear in a way that protects them from shorting to anything else, or to each other between the connections you made on purpose. Dipping the whole works in a can of Plasti-Dip is one of my favorite methods.

For "spade connector" you'll want the exact terminals that are used in the Toyota connector. You won't find those in boxes at the auto parts mart, but you can pay a handsome price for them at the dealership.

Because resistors aren't perfect, this will probably give you a zero-signal that is close to but not identical to the zero signal from your steering rack. The ECU has a set-up mode where you tell it "look, this is zero". If you don't do that it will probably want to constantly "assist" you off to one side.

The fast way to say "this is zero" is to use the special Toyota hand-held scan tool. There is a way to do it by wiring a temporary LED indicator to the steering ECU and some nimble fingerwork with jumper wires at the DLC3 diagnostic plug by the driver's knees. I recommend looking it up in the manual because if I try to describe the procedure you'll be convinced I'm pulling your leg.

Another place you can put the needed temporary LED is on the instrument cluster; I permanently attached one there just to not have to futz with it. I think earlier in this thread I linked to a thread that shows it.

-Chap

 

Congratulations, GW; I'm pleasantly surprised to see the low prices for the steering rack and inverter. Glad to hear that your car is running well now.

 

So let me get this straight, in order to bypass the power steering issues you just disconnected the EMPS ECU? How hard was it to steer?

what battery you selling the HV? if so how much u want for it?