Water Pump

I was putting it back in, but I dropped the water pump and the plastic ring
that attaches to all the blades broke... so I put in the one i bought.
I was not happy!

 

Oh lol hahaha

 

Measured both frequency and duty cycle using a Fluke 87V voltmeter. Did measure 25.000Hz at the WPI line to confirm I was measuring in the right cable.

Monitor mode was used to keep the engine running.

Once the engine reached 90C, the WPI line measured 84.8% as duty cycle, and it was constant from that point on

With the MIN/MAX function enabled, measured the WPO line for 5 "cooling fan runs" cycles (~95C back to ~91C is one cycle)
* 151.85Hz was the min value (4530 rpm)
* 152.05Hz was the avg value (4536 rpm)
* 156.02Hz was the max value (4655 rpm)

Any comments? Is the engine pump working OK?

 

Given that what I observed a couple years ago was

it seems like yours is right in the same ballpark.

 

Do any of you know where the WPO and WPI cables go thru in the engine bay? Is there an easy way to replace those cables without having to take apart the whole intake, EGR stuff to trace those paths? If so, please let me know.

I'm having a problem with my water pump. After going thru some threads here on PC, the relevant pages of the 2010 repair manual and experimenting with my two pumps (the old one still on the engine and the replacement used AISIN pump), I doubt I have the WPO and WPI cables shorting after I did the J0V update at a local dealership and I had the old pump running intermittently, first with the CEL and P261C code and then without either of the two after a scan and clearing of the code :/

 

The two individual wires carrying WPO and WPI are part of the engine wiring harness; they appear at the water pump connector, of course, and their other ends are in a multipole connector where that wire harness plugs into the fuse box; those connections are shown in post #36 in this thread.

With that, you know where both ends of each wire are, which is enough to test continuity with a meter. I would not jump to any conclusion about the wires being broken or shorted unless meter readings confirm that is the case.

If confirmed, then you would face the choice of repairing or replacing the engine wire harness. The economics depend on how many wires are damaged. Repair may be preferable if it is only one or two. More on repair here.

 

Thanks for your reply, Chapman.

I made some measurements, though I don't fully understand them (

Here they are:

with 12v battery negative terminal unhooked for 20 mins:
1) D13 - 2 (NWP) to A57 - 11 (WPI) _ 0.6 ohms
1.1) D13 - 2 (NWP) to DA2 (WPI) _ 1.4 ohms
1.2) A57 - 11 (WPO) to DA2 (WPI) _ 0.5 ohms

2) D13 - 4 (SWP) to A57 - 10 (WPO) _ 0.6 ohms
2.1) D13 - 4 (SWP) to DA2 (WPO) _ 0.9 ohms
2.2) A57 - 10 (WPO) to DA2 (WPO) _ 0.5 ohms

3) DA2 (WPO) to body ground (BG) _ 38.9k ohms
3.1) D13 - 4 (SWP) to BG _ 38.9k ohms

4) DA2 (WPI) to BG _ 1.6k ohms
4.1) D13 - 2 (NWP) to BG _ 1.6k ohms

For the last four measurements, 3; 3.1; 4, and 4.1, I had the A57 connector clamped to the ECM, otherwise the multimeter reading was 1 (open circuit?). I twisted the harness at A57 but the reading remained 1 when unhooked.

For these measurements, I hooked up the 12v battery negative terminal and here're the multimeter readings:

with ignition on and the D13 connector unhooked:
5) D13 - 1 (+B) to BG _ 12.06 volts
6) D13 - 2 (NWP) to BG _ 12.05 volts (observed a slow drop by 0.01 volts to 11.99 volts, then removed the probes for other measurements)
7) D13 - 4 (NWP) to BG _ 0.01 to 0.02 volts (fluctuating)

with ignition off and the 12v battery hooked or unhooked:
8) D13 - 5 (PGND) to BG _ 1.6 ohms

The relay and the relay terminals seem to be fine in the fuse box.

What I observed was that when I turn the car on in Ready mode, DA2 (WPO) to BG voltage reading is 0.01 to 0.02 volts, then jumps to around 7.5 volts for a few seconds and and then back to 0.01 volts. The water pump runs intermittently, only when the voltage goes up.

When I broke the WPO line on purpose, I got the P261C code and CEL on MID which I didn't have before. The water pump ran constantly at a high speed (I guess in fail safe mode at over 6k rpm?). Then I broke the WPI line as well and I got the P261B code. I didn't have these two codes when the WPO and WPI lines were intact. The live data readings before and after breaking the lines are 0 rpm and a duty cycle of 6.25% when ignition is on and straight to 62.5% when in Ready mode. I'm using an ELM327 v1.5 bluetooth dongle (Panlong PL-B02) and the Car Scanner android app.

 

Thanks again, Chapman, for your reply and the extensive post back in this thread about how the control circuit works.

Initially, I had the P261C code which was cleared by a mechanic and the pump kept running normal for some time. Then it had intermittent surges and slowdowns without code or CEL. I replaced the pump about a week ago and now everything works fine.

I must have been wrong about the ECM wiring. It might just have been a coincidence because the pump started underperforming after they did the update at a local dealership which was really confusing (

 

Glad it's working now. Sorry I didn't see your earlier post ... had an eight-day internet outage (in fine clear weather; a total self-own on the part of my provider).

 

I read almost this whole thread this morning, (my memory is hazy but I think I got the basics) along with some other research and came to the conclusion that I should try and burp my coolant system and so I put it in maintenance mode and was watching to see whenever it would swirl and it didn't but the coolant temp got to 171°f. This brought me to believe that my water pump is either going bad or is already. I haven't had a light or any codes but the fan starts shaking and getting crazy and trying to burp it didn't seem to do anything. I've watched videos on replacing it and it looks easy enough. Can I get an OEM water pump off of Amazon or do I need to get it from Toyota directly? Any other advice you can give me? When replacing the coolant after do I need that special tool to put it in the car without air bubbles? Thanks in advance.

 

Also, I'm still trying to figure out if it would be in my best interest to put more money into this car instead of taking my insurance money to buy another. I already passed up on the $1,500 to give them my car. They paid $5,700 since it has 266k miles. I've been able to put together 6k so far and have a parts car I guess. Man, I love this car.

So far in Las Vegas I've test drove a couple but one had too much wear for 135k miles and the other has a battery cooling system warning. I was ready with my ODBII scanner, Dr. Prius app and a car scanner app.

The clues that led me to the water pump problem started before I hit the rock. All it was doing was the fan was tapping occasionally when the AC was on. Then it did it after driving across town but it was more erratic. No light that I noticed and no code. I might have got that update at the dealership when I first got the car but I'm unsure.
By what I read here, it doesn't throw a code about the pump since the propeller blades melted, off then spinning too fast and not actually pushing the fluid to cool it. My scanner said the fluid was 171°f. I was in maintenance mode but turned the car off then turned it on to get a temp reading and I saw no light then turned the car back off.​

 

That's what I thought, too /
I changed the waterpump & the thermostat last weekend & it was NOT as quick & easy like in the youtube videos....

 

Never heard of this. Which fan?

 

The AC fan and now the engine cooling fan. I guess 171°f isn't that hot yet for coolant temp.
Also I saw that the inverter cooling system is separate from the engine cooling system? Does it have its own water pump?

 

Yes, it does.

Come to think of it, the A/C fan in my dad's Hyundai started shaking and getting crazy when there was a mouse nest in it.

 

Right, great observation but this is happening after freeway driving while under a load. Fan is clean and the bering or blades don't have any play. I haven't got a code or light but it seems that I have oil residue around the valve cover gasket now. Also have an ongoing oil leak around the passenger back side of the engine but I don't let the oil level go low. I also haven't over filled it. No lights.
I'll watch my obdll app and watch the temp in maintenance mode too see if I can figure it out.
How do I tell if a temp sensor is working?
I have a water pump on the way. I've already got the thermostat.
I don't have any smoke coming out tailpipe and the brand new oil I put in still looks good.
It almost seems like nothing is wrong but the fan is telling me it's in distress. Summer is tough but it didn't do this last year.
Seems like the heater wasn't that great unless I was moving or reving the engine during the winter. I thought it was normal for an electric heater. I assumed since the ac was electric that heater was too.
I appreciate your assistance.
On another post I liked a comment (ChapmanF) where you said yours was making noise. I didn't see your outcome of that on that thread. You had said you didn't bother to get the stethoscope out yet. Was your fan motor bearing going out or was it just under a load? What was your fix?
Thanks again.

 

Hang it in a pot of water on the stove next to a thermometer you trust.

I decided it didn't sound bad enough for me to care, and hadn't given it another thought until now. Thanks for that.

 

I did the suspended in pot of water brought to boil test (years ago, ‘nother car) with both the old thermostat and replacement. The new one opened sooner as temp climbed, and IIRC closed sooner too, when I let temp drop. Also, frayed gasket edges where evident on the old one.

 

I thought the question was about a temp sensor, not a thermostat. But the hot water pot test does work for both.

 

Ah woops: I see something suspended in water, harken back to my sole experience.