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Grumpy Old Man
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I'm a couple of weeks off doing just this in my car.

I have a nerdy mate that's done all of the ground work but I'll wait and see how it all goes before saying "it's easy" ;)
 

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The signals that the ECT needs are actually split off in the wire harness, I have a AEM, the only thing needed was to wire in a relay for the converter clutch, the AEM controls lockup, the ECT still controls the shifts.
 

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Discussion Starter #5
I can tell you right now that the ECT requires a signal from the ECU in order for overdrive to work. I don't think it needs a signal for lockup. the ECT does that on its own.

I wired up an A340H(4x4 tranny) to a 7M ECT. I was using two diagrams to figure out the wiring, and between 88-89, the colors if wires they used switched around a bit and made it a little confusing. I hooked up the wrong wire for the ECT(also known as OD) and it did not work.

I just wonder if the other 3 wires are needed. L1,L2,L3, and what type of signal they send to the ECT.

Maybe I will cut those wires on the truck I am working on and see what happends.
 

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Grumpy Old Man
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The signals that the ECT needs are actually split off in the wire harness, I have a AEM, the only thing needed was to wire in a relay for the converter clutch, the AEM controls lockup, the ECT still controls the shifts.
Doesn't the ECT require a signal from the TPS as well?
 

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Discussion Starter #9
The signals that the ECT needs are actually split off in the wire harness, I have a AEM, the only thing needed was to wire in a relay for the converter clutch, the AEM controls lockup, the ECT still controls the shifts.
Did you find this to be better than the AEM controlling shifting?

What about overdrive signal? I know for a fact that wire is needed.
 

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Grumpy Old Man
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SR: Can you elaborate please?

I'm going to T the Solenoid shift from the ECT wires into my Standalone on spare AUX channels so I can datalog what they actually do then look at wiring the Standalone to mimic the ECT so I can remove it.
 

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Discussion Starter #11
Well, all I know is that the vehicle I was working on would not shift into OD until I had that wire hooked up to the ECU. I believe the other wires are not needed as they are probably feedback wires to the ECU to retarard timing during a shift to improve shift smoothness.

I bet if you just cut the other 3 wires, you would get much quicker shifts. I tried to verify that this afternoon, but the fuel pump died. Truck had been sitting for awhile awaiting a new engine.

As long as the ECT gets a speed signal(either from the guage cluster or the sensor on the tranny) it will shift just fine. But again, cutting L1, L2 and L3 from the ECU...I don't know what that might effect. I will try to get it running this weekend to know for sure. If the 7M ECT has some good shift points, this is likely a mod that the MKIV guys might even like, since some of them don't like how the AEM shifts.
 

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Discussion Starter #12
Ok, I did some testing and I was wrong on one thing.

YOU DO NOT NEED the overdrive wire connected to go into OD. I had it hooked up wrong before and therefore it was grouned out and did not work.

My test:

Hooked up speedometer guage to drill and I could run that up to 80mph. I hooked up power to the needed parts on the ECT and hooked up lights to the solenoid wires.

I did not hook up the TPS so I could not get all that accurate readings on shift points, but I do know that it did go through all the gears just fine, and I got lock-up too.

I still am unsure about the other 3 wires going to the ECU, it seemed like they were input wires from the ECU to the ECT...which means the ECU has some control over shift pattern. What I don't know is how the ECU knows when the ECT is shifting...there is no feedback wire. All the wires were a constant, and only changed slightly as speed when up due to a voltage drop when lights came on, but nothing to signify that the ECT sends signals to the ECU.

If someone wants to pull those pins out on thier ECT and drive around that would be really helpful to this.

So for my conclusion is, as long as you have a TPS, and a speed signal from the tranny or the guage cluster, the ECT is a stand alone unit.
 

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90T
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All the ECT to TCCS conections appear to be signals going from the TCCS to the ECT (i.e. inputs to the ECT). ALso, the cruise control can command the transmission to disengage O/D under some conditions.

pin 17 (OD1) is to prevent O/D engagement with a cold engine.
0V with engine temp < 70deg C
5V with engine temp > 70 degC


pins 2 3 and 4 appear to be related to throttle position, but exact algorithm is unclear. Here is what I can figure out, but more data is needed to be certain.

let 5 volts be logic 1 and 0V be logic 0, then looking at the pins, it would seem that the throttle position is being digitally encoded by the TCCS with pin 2 LSB

(I am struggling to make this table legible... LOL)



TPS______ 4 3 2 (ECT pins)
======================
idle_____ 1 1 1
+________ 0 0 0
++_______ 0 0 1
+++ _____ 0 1 0
WOT______ 0 1 1


If someone can actually monitor these lines during operation maybe this could be verified, or proven incorrect. Note, the TSRM says the LI,L2,L3, OD1 logic voltages are 12V and 0V and the TEWD says 5V and 0V.

Also, note that the ECT diagnostic pin Tt has 8 voltages (0, 1, 2, 3, ....7V) that correspond to throttle position. This further supports the idea that the LX inputs are binary encoded throttle position (3 bits resolution).
 

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Discussion Starter #15
Yes, I just verified that as well.

The TPS input to the ECT is only to let the ECT know if you completely off the gas, or not. That is also a logic circuit, and not variable which I was hoping.

L1, L2, and L3 are use to control logic to the ECT based on RPM/speed/TPS from the ECU.

From this it seems that the ECT is pretty much is just a switching board. The ECU dertermins the logic on how to shift and then signals to the ECT through those 3 connections. It is interesting though, that the ECU never knows what gear the tranny is in, it can only assume based on speed and RPM.

With this in mind, it still seems very possible to use this in conjuction with the AEM.....but I don't see why you would need to do that.

For stand alone units, it looks like the ECT is worthless.
 

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Grumpy Old Man
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Great info guys all this is going to help next month.

I have a table the guy at Wolf wrote for my bud last year I'll see if I can dig it out.
 

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Grumpy Old Man
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setings for wolf 3D V4+ toyota ECT ECU control
Version 4.72 firmware required
***yet to be tested***

AUX output 1

set AUX mode 1
set on value to 35%
set off value to 107%


AUX output 2

set AUX mode 1
set on value to 15%
set off value to 65%


AUX output 3

set AUX mode 1
set on value to 7%
set off value to 25%


AUX output 4

set AUX mode 1
set on value to 50%
set off value to 85%

From Allan over at Mk3Tech and Steve at Wolf.
 

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Bumpin' from way back.

...So for my conclusion is, as long as you have a TPS, and a speed signal from the tranny or the guage cluster, the ECT is a stand alone unit.
I am going to use the 2JZ-GE ECU/harness and was considering the 1JZ-GTE auto tranny, until now.

Does this actually mean that I can use the 1JZ auto bellhousing and keep the stock MKIII auto tranny/ECT, by just ensuring that the TPS signal gets to the ECT (tapped from the 2JZ-GE ECU) and get the speed signal from the speedo gauge (pink wire) to the 2JZ ECU (SP1, SP2)?

TIA!!
 
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