Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v

Yes! Again please ignore the switching of the wires.




iPhone ?

 

Better than ignoring ... if you did switch them, it would be good to switch them back.

 

brother i switched them back a while ago lol i was just hoping that maybe i had a different pinout or something but now its a whole different situation.

My egr just unplugged for now. gonna experiment a little.

 

That could be. The Electrical Wiring Diagram (more info) shows that the terminal/signal assignments at the connector for the EGR valve assembly weren’t changed between generations, but some of the wire colors were:

Terminal 1 (EGR4), Light Green
Terminal 2 (+B1), Black
Terminal 3 (EGR2), Violet (2010) or Red (2016)
Terminal 4 (EGR1), Red (2010) or Pink (2016)
Terminal 5 (+B2), Black
Terminal 6 (EGR3), Yellow (2010) or Beige (2016)​

This doesn’t imply that any wires need to be exchanged, however, since the terminal assignments at the ECM were also changed. The wire harness needs to match the ECM.

If you do the Active Test for “Control the EGR Step Position,” be sure to see the instructions and important restrictions that appear in the Repair Manual procedures where this test is used, such as the one for DTC P0101. (Ignore the rest of that procedure, unless it applies for some other reason, of course.)

In the fourth-generation Repair Manual, under Engine/Hybrid System: 2ZR-FXE (Engine Control): SFI System: Data List/Active Test, there is a plot showing the relationship among EGR step position, engine speed, and intake manifold absolute pressure, and some hints on how to do the test.

 

Do keep in mind that when you unplug the valve, the ECM can immediately detect that, and its failsafe reaction is to alter the ignition timing.



... the upshot being, whatever you notice about how the engine runs with the EGR valve unplugged, isn't just about the EGR.

 

Tracking on this situation, I thought about that possibility. Definitely makes sense.

 

If need be, could just EGR valve be reverted to 3rd gen (preferably revised one). Would it mate with pipe and cooler? Just thinking there's maybe "ireperable differences" between 3rd gen ECU and 4th Gen valve.

 

Good question!

We tried and we failed at that. No possible way to do that.




iPhone ?

 

We can actually find that out if we continue proceeding methodically.

So far, the indications are the valves are extremely similar in their operation.

There are some measurements that could still be made and haven't yet.

 

Yes, that was a short fix but you can’t drive like that for a long time


iPhone ?

 

@Mendel Leisk, where were you getting the 4th gen manual excerpts you were posting earlier? Did you have access, or were you reposting excerpts somebody else had?

 

thank you for all the help

 

I have a full 4th gen manual, that someone downloaded, from Toyota Tech Info I assume. I "print" excerpt pdf's from that as needed.

Inoperable links, that point back to Toyota Tech Info website.

 

Ah, a not uncommon situation.

Is there a chance, when you have a moment, you could check around the early part of the engine diagnostics section, maybe right after "terminals of ecm", to see if there is an EGR waveforms illustration similar to the 2010 one in #346, and maybe in the P0403 troubleshooting section for a circuit illustration like the 2010 one in #344, and drop those in here for the record if you find them?

 

@michaud85 kindly posted the fourth-generation waveform information in #356; it’s the same.

I’d post the fourth-generation wiring diagram from the Repair Manual information for DTC P040314 (the new way to spell P0403), but it shows the internal connections of the EGR valve assembly in exactly the same way as the third-generation diagram. There are no other substantive changes, just new designations for the ECM terminals, fuses, relays, etc., and symbols inside the ECM showing that its EGR1 through EGR4 terminals are each connected to chassis ground through an NPN transistor in series with a resistor.

 

Mendel mentioned the Electrical Wiring Diagram manual. That's separate, and it's where the most complete and detailed diagrams would be found, but the Repair Manual usually has simplified diagrams of the part of a circuit that is relevant to a particular troubleshooting process.

In the case of EGR, P0403 is the code for an electrical anomaly detected involving the valve (or at least, that's the code in Gen 3; I think that's in the standardized range).

So if you find the troubleshooting workup for P0403, probably only a few pages long, and flip through it, that's where you're likely to find the same simplified diagram I posted earlier (which was the same thing, from the P0403 section of the Gen 3 Repair Manual).

Edit: guess I must have posted this reply this morning without refreshing the page first, or I would have seen Elektroingenieur's response.

 

I finally got tired of having my only car sitting in the carport, so I had it towed to the dealership. Apparently the lead wire to the camshaft position sensor was only hanging on by a couple of threads (which is why I was still getting voltage when I tested it with a multimeter). After replacing it with a new connector, that code disappeared.

They then discovered another issue (and this one is admittedly my own foul-up): I had installed the water pump from the 3rd Gen to the 4th Gen engine, assuming they were the same (the one from the 3rd gen only had maybe 1k miles on it). As it turns out, the water pumps between the 3rd & 4th generations are not compatible (the way thermostats are). They discovered this when they tried to bleed air out of the coolant system and were unsuccessful - the pump sounded rough, and they triggered a water pump code. Apparently the spline on the 3rd Gen water pump is longer than the one on the 4th Gen. I told them I still had the 4th Gen water pump at the house, so I could just use that. They were going to charge me $250 to install it, so I decided to drive down to the local Hardees (Carl Jr's for anyone on the west coast) and install it myself. Had it installed and bled the air out in about 45 minutes. I erased the water pump code, and it did not come back.

Everything seemed fine so I started to drive home. After about a mile the coolant temperature spiked to about 240° F (I was monitoring it on my OBD device), so I pulled off the road. Because of the lack of codes, I assume the water pump is working. The thermostat is working because there was a noticeable drop in coolant level after about 180° F, indicating that it opened. Both radiator fans are working. I suspect that maybe there is more air in the system, and will require jacking up the front of the vehicle to bleed it (I've read about others having to do this).

Not knowing where I might end up from here, I thought it wise to just let them deal with everything else from this point on. I've had my car in the carport for 6 months and need it to get to work and school. Can't be depending on others to drive me around anymore, and I can't have it towed to Toyota every time I need access to Techstream.... I really need to find a copy of this and learn how to actually use it.

 

On another note..... before having it towed to the dealership I removed my hybrid battery and placed it in my father's Prius so I could charge it up. I wanted to avoid the dealership blaming all my problems on 20% battery power, and then attempting to sell me a new battery. Not saying they would necessarily, but just in case. There are good instructional videos of this on YouTube as well - this turned out to be far easier than I would have thought, though it did take two people to lift the battery out, due to the awkward position.

 

My eyes are being opened ... I had been following these threads, and without thinking about it I was just assuming that anybody diving into a cross-generation engine swap surely already had Techstream and both years' repair manuals.

 

Yeah lol I am honestly pretty disappointed in some of the mis information that washwas available on this swap. I was going off that fact that like 2 other people did these swaps and were not having any problems enjoying power mode and frolicking happily. I'll consider myself lucky i could be having a much worse time like Jacob, which maybe I will soon.

I was getting same day replies from people on the threads so I had alot of confidence that it was going to be pretty smooth. I have done these kinds of swaps on Honda's before so I didn't think this was too crazy.

References have a place for sure esp for part numbers and circuit diagrams but alot of times the manuals leave a lot of information for you to interpret anyways. A manual will only get you so far, it doesn't teach you how to use the tools in your own tool box or how to be creative and make the machine and tools work. What do you do when the manual doesn't solve your problem? You consult someone who has done it. Thats where these threads shine, they function as often rudimentary but sometimes complex manuals. As powerful as multiple interpretations of experience and manuals in some cases.

I purposely left all gen 4 components right on the gen 4 engine and adjusted my wire harnesses accordingly. I only had to bend the gen 3 exhaust manifold on the little EGR pipe.

Now I have to play games with the vehicle to get gen 4 EGR working smoothly with ecu or I could probably just make some sort of mounting plate for a new gen 3 EGR to bolt on easily to all old gen 3 stuff.

Gen 3 egr is notoriously lame as hell though so it's not a very attractive option, althoug EGR may not have so many problems when the oil rings are still working haha

Decisions....