AEM EMS and the A340E not kicking down

[Supra0089]

So I just did an entire engine build, put in a new wiring harness, and installed an AEM EMS.

Car runs and drives amazing etc etc.

The only issue is, under WOT it does not climb over 3k rpms if it's in drive for any gear at any speed. If I manually shift the auto tranny, it will hold gear until I shift it just fine. It also does not kick down if I'm cruising and then go WOT.

Driving around town, or driving normally, it shifts fine; but on accelerating it shifts up as quickly as it can to the next gear no matter what % throttle I'm giving it.

My tuner said that the AEM seems to only communicate with the auto tranny for torque converter lockup and that's it. The install directions do not call for any special lines to be hooked up to the tranny other than the torque converter wire.

Does anyone have any experience with AEM EMS's and 7m auto trannys that can steer me in the right direction. Manually shifting isn't a big deal, but I would rather it do it on it's own sometimes if I want to go into passing gear while drinking coffee or something...

Thanks in advance

 

[Nick M]

AEM is not compatible with the A340E. You need a stand alone like Suprastick. The TCCS sends the throttle position sensor signal in lue of the throttle valve cable. It won't upshift.

 

[IBoughtASupra]

^ Not True

I believe Devin has run a 7M Auto on the AEM. Ian told me it would work with a standalone but you will just need to feed the TPS signal from an output to the trans computer.

 

[Supra0089]

I'll message Devin.

 

[IJ.]

There is NO KICKDOWN Cable on a 340....

It's a Line pressure cable, A standalone will run but it chews up a few outputs to send the correct signals to the ECT.

 

[Supra0089]

Thanks for the Clarifying IJ.

Does anyone have any links for how to wire in the AEM to talk to the ECT? Or is there a possibly to add a piggyback that does the same thing?

Thanks.

 

[IJ.]

Here's how I did mine for the MoTeC>

You want to assign one of the outputs as an AUX table. (fucntion 3). You need three AUX tables assigned to three AUX outputs.
then set the parameters to switched for the output type.
Then, in the tables. Add TPS on the X axis ( add for every 5 break points basically using all 20 sites) and nothing for Y axis (since we want to mimic the TPS pass through to the ECU).

This should get you close. You want to basically use the following for each aux table (need three of them).

For Aux Table 1 (L1 on the ECT). 35% to 100%. duty cycle should be Zero percent (0 V)
For Aux Table 2 (L2 on the ECT). 15% to 65%. Duty cycle should be Zero between these two sites.
For aux Table 3 (L3 on ECT) Between 7% and 25% & 50% to 85%. Duty cycle should be zero percent.

Now one thing to keep in mind is that the motec outputs 12v through these so you will need to put an inline resisitor to make them 5v and prefferably 4.5v

You will also need an Idle on/off Output.

 

[Supra0089]

Thanks IJ. I'll go over it with my builder and Tuner.

 

[IJ.]

No probs, I believe there's a Camry TPS you can use that does it all for you and saves a bunch of Outputs.

 

[Nick M]

^ Not True

It is. I take you haven't yet read the rest.

As stated, it doesn't work because it needs the signals that AEM doesn't provide. Sure, you can fabricate.

 

[Kristian_Wraae]

The ECT needs the L1,L2 and L3 signals from the ECU. You can make those quite easily with the Arduino platform. The signals are the same as the ones needed by the TEMS computer for the squat function.

I have a 2JZ-GTE and TEMS and a friend of mine has done a small dedicated print from the Arduino platform that inputs the TPS signal and outputs the L1, L2 and L3 signals. It works perfectly with the TEMS so I think it'll work fine too with the transmission computer. If you are interested I can propably get you a box that will make those signals. The box is programmable so you can tweak it if you now how to program it. (it is very simple).

 

[Terry steward]

Some valuable info here,,,i have had to change Manually if I want to play,since having the AEM fitted 4/5 Years Ago,,it isn't a big deal,,but It would be nice not to have to.

 

[Nick M]

The ECT needs the L1,L2 and L3 signals from the ECU. The signals are the same as the ones needed by the TEMS computer for the squat function.

I want to make a note. The trans computer uses TPS and THA, which is engine coolant temps along with the speed sensor. THA has no function with the TEMS. The ECT (electronic controlled transmission) needs those signals for correct timing and lock out of high gear when cold.

 

[Kristian_Wraae]

The coolant temp is just to help warm up and could probaly just be held at 5V. The other signal is just the idle signal 0V at closed throttle. Should be there no matter what ECU you use.

 

[Nick M]

The coolant temp is just to help warm up and could probaly just be held at 5V.

I guess you can't read.

 

[Kristian_Wraae]

Well you guess wrong.

 

[jetjock]

...The coolant temp is just to help warm up and could probaly just be held at 5V....

For the benefit of other members this is wrong.

 

[Nick M]

http://www.autoshop101.com/forms/AT10.pdf

Page 12 of 21 for those that want to read about locking out gears when the temps are too low. In fact, it would be beneficial to read the entire pdf even if you are not solid on automatic trans operation.

 

[3p141592654]

The inputs to the tranny from the ECU are L1, L2, L3 and ECT. The IDL input comes straight off the TPS signal. There is no THW input per se, but ECT codes for THW

Inputs that affect ECT are the status of the NSW, vehicle speed, rpm, and THW. THW trip points are 35C (40km/h) or 60C (60km/h).

 

[Nick M]

There is no THW input per se, but ECT codes for THW

Which is why AEM says you can not use the A340E with their stand alone. It is not a parallel feed from the harness.