A Prius ECT Spoofer MCU Controlled

I just got mine on Monday and finally had the time to install it tonight. I did have to clear up some confusion installing on my 2008 because the instructions said to connect the green wire to the white wire with the widely spaced blue dots next to the red wire. But on my Prius, that white wire didn't have enough exposed length for me to see any of the blue dots (the other white wire next to it has closely spaced blue dots on it which is what caused the confusion).

Winston replied to my question and said that the correct white wire is indeed the one directly next to the red wire, and not the next white wire past that. Being a total geek, once I had that clarification (which I was 90% sure of anyway after hours of googling), I couldn't wait for morning so I pulled out my flashlight and went out at 3AM to do the install. Probably not the smartest approach, but I couldn't help myself!

It seemed when installing it that the white wire may have been a little thicker than the red and brown wires I was also tapping into, because when I clamped the scotchlok down on the white wire, if I viewed it from the side closest to the white wire, I could see it was a bit W-shaped. I went ahead and tested it anyway, and the lights all lit up so I figured it was working fine. Only thing is, once the temperature got high enough on my ScanGauge for it to take over spoofing, nothing happened.

It drove fine and everything else seemed normal though, so I drove to a nearby gas station that had great lighting and pulled the glove compartment back out to troubleshoot the problem. As I was trying to twist the scotchlok on the white wire around to double-check the connection, the white wire popped right out of it! I obviously hadn't clamped down quite hard enough to secure it fully with my pliers when installing that one. I managed to work the wire back in where it belonged and crimped down harder as best I could with my multitool. This time when I checked it, that W-shape wasn't there anymore, and aside from the insulation being a little warped around the teeth, it was pretty much straight.

I hopped back into the driver's seat and powered on, and low and behold, the flashing heartbeat light that indicates spoofing started fluttering away, and my ScanGauge now indicated between 168 and 172 degrees F. Spoofing success!

I drove it around a bit longer running some late night errands and when the coolant got up above 170F the blue light went solid and my ScanGauge started reporting the actual temperature again all the way to normal at around 181-184F. I built up a good SOC on the HV battery, parked, and set the heater to HI and let it run until the temperature dropped enough to start spoofing again (that only took a few minutes-- it was 65F outside), then waited another 10-15 minutes for it to drop low enough to stop spoofing at the low side to verify that it was working correctly.

Once it hit 106F, spoofing stopped and it started up the ICE to warm it back up again. I shut it down there to finish my last errand, and when I came back out and powered on again, the engine block had had enough residual heat in it to raise the coolant up above the 114F cutoff again, and it started to spoof the temp to 170 right away, and I was able to enter S4 operation as soon as the 50 second warmup cycle completed.

Next I just need to install an EV mode button, and between those two simple mods, I should be able to improve my shorter commute mileage significantly, which will have a noticeable effect in the longer term too.

Thanks to Winston (ccdise) for creating this nifty little device! I can't wait to track my next couple tanks of gas to see how much difference I see. It'll definitely help out at work during the longer gaps between deliveries where I have to shut the car off-- I'll be able to spend a lot more time in S4 and not trying to get it back there and time it to where I can stop and sit for the idle check dance. This is a very handy little mod, and certainly worth the price! It's very well assembled-- Winston's great soldering skills are on display for sure. My hat's off to you sir!

 

I will be getting mine in the post soon. I plan to use my Canview V4 to collect the raw Canbus data and graph results and post them on this thread.

 

babybird: Thanks for sharing your first experience with the spoofer. Mine is on it's way to Germany (thanks, Winston) and I hope that I'll do as well as you with installing it, since I'm a a total geek too. Kurzer's video and your reporting should be helpful.

Kurzer is not participating here, so I'll share with you the most interesting parts of his reportings in the PriusFreunde Forum.

Kurzer is using a scangauge II. He reports the spoofer is working fine, allowing his car to reach S4 very soon, much like babybird reported.

He had however an interesting observation that may also help understanding some of the feedback from other users:

If the car is started again after a stop, and the coolant is between 48 and 66 °C, the car starts in S3b, not S4. If one starts driving right away, the car "drops" in S3a and behaves as if it had no spoofer. To remedy this, he puts the PSD in P and depresses the gaspedal to force the ICE to ignite. Once done, the car starts driving immediatley in S4.

This also shows how useful it is to monitor the coolant temperature with a scangauge or the likes. I'll have to buy one...

Jan

 

Just to ensure that I'm understanding correctly, if the car is shut off for some period of time, and then powered back on into Ready mode, in order to get into S4 immediately, you must stay in Park and press the gas pedal to force the ICE to start running before you drive? Or do you have to do this after the 50 second warm-up period and the ICE turns itself back off? Or is it sufficient to let the 50 second warm-up complete on its own to enter S4 right away?

Sorry, I wasn't quite clear on your explanation, and the Google translation didn't quite help enough to clarify it to me.

And thanks for the info!

 

I'll transfer your question to Kurzer, and report back ASAP.

Jan

 

OK, here is kurzer's answer.

In the conditions depicted above, he recalls the HSD will start in S2, because of the temperature of the coolant. The spoofer will cheat an the HSD will read a > 70°C temperature. But due to the fact we are in S2, S3b is reached first, and the ICE remains shut down. In order for it to advance into S4, it needs to be on, somehow, to put it into S3a. He points out several ways of forcing it to do so.

Besides starting in P and force the engine to start, one can also drive and depress both brake and gas pedals (kurzer calls this "Stepdance"). P is practical, since that's where the system is when starting (ready).



Winston and babybird: do you think this is a plausible explanation? Was I clear enough?

Jan

 

Here is an observation to add to the clues to how things work. I have been experiencing dropping out of S4 while driving. See this thread for details: Drop out of S4 for no apparent reason? | PriusChat. I always use the spoofer and in the morning I also use EBH. These days in the morning the temperature is around 60s. I never see S4 drop out in the morning unless I forgot to plug in the EBH the previous night. In the afternoon the temperature is around 70s, and I consistently see S4 drop out. The only exception is when it is really hot, in the 90s, then there is no S4 drop out. So this is as if even though we spoof the temperature, the ECU somehow knows the spoofed temperature is too good to be true so it does not let us get away with cheating that easily.

 

Thanks 2009Prius. What is EBH? I do not understand how this could happen at one temperature range, and not at others. Any ideas around?

 

EBH = Engine Block Heater. It pre-heats the engine block to somewhere around 50C. There were some speculations tossed around in the original thread but nothing certain.

 

I did a "hot start" test today and posted the result here:
Drop out of S4 for no apparent reason? | Page 2 | PriusChat
There was a steep uphill coming out of the parking lot so I couldn't really go gentle.

 

I tried an idea to turn the spoofer off and on a few times during the trip so at least the ECU doesn't see near-constant temperature for a long time and gets suspicious. But it still drops out of S4 as usual.

 

Just did my install today. Being an electrician I thought it would have been a piece of cake. Not so. After the install it spoofed in reverse as it was giving a spoofed value of 35degC instead of the real 45degC. The LEDs were all working. Strange. I got my DMM out and started making some voltage measurements on the plug. Got a measurement between the black wire and the green wire but no volts between black and red wire. OK lost connection to the 5v on the scotch lock. I then removed all the scotch locks and soldered the three connections, used electrical insulation tape and cable ties to make sure all connectios were well insulated and could not short out. Made each connection on a different point of the wire compared to the other two to eleiminate the chance of a short circut. Burned off the wire insulation with my soldering iron to expose the copper for soldering. Whilst I was making measurements with my DMM all the pins came out of the plug. I then found a photo of the plug with wires in this thread so I could follow it and put back the wires with pins back into the correct hole of the plug. Also had to bend a piece of each pin so it will catch inside the plug and not come out.

Anyhow after all that it works just right. I started the ICE in park and I watched the ICE temperature rise to 47degC and then jumped to 76degC. ICE stopped. Then I let the ICE cool down and then watched the ICE temperature jump from 76DegC to 45deg.C. Perfect.

Thanks Winston.

Anyhow I hope that users see the importance of keeping an eye on the ICE temperature. Anyhow try disconnecting the red wire and watch it spoof in reverse.

On further thought maybe there should be a diagnostics table in the instructions to show possible install faults and remedy.

 

Hi Winston, Hi all,

today I installed the ECT spoofer. Installation was easy due to the very exact installation instructions sent with the spoofer an the "training scotch lock" . Good idea...
I'm using it in a Prius Gen2 with 4kwh enginer kit. The feeling is very good, relaxing , often as possible to drive in "automatic" EV mode.

I attach two pictures of some data recording with the Crecorder , showing the temperature change from 46°C to 76°C.

You may see as well the RPM of the ICE and speed.

Regards EVplus - Guenter

 

"proof" of the action of the ECT spoofer :

the attached pictures shows the action of the ECT spoofer. at ~46°C when the action begins, the temperature line jumps to 76-78°C, showing a serrated line. When the engine temperatur gets over 77-78°C the spoofer action is disabled to assure sufficient engine cooling ( my interpretation). If the temperture falls below 78°-76° C the ECT spoofer action starts again.

The second picture shows a sequence of high temperature at better resolution.

 

For what it's worth, I've never been able to directly enter S4 no matter how hot my engine is when I start it. It always goes through S1 first and then to S3 (provided the temp is high enough that the spoofer is active, of course). The duration time in S1 does vary significantly (sometimes it is only a few seconds) depending on how long the car was off, though (cat converter temp effect?). I know it's in S1 due to the higher RPM and IGN=-10.

I read somewhere on PC that there was a difference between the US Prius and those elsewhere, though, with regards to which stage you can start up in.... Something with the coolant thermos....?

 

I extended the wires and added a toggle switch as shown in the photo above. It is a tight fit.