bump

 

Are you connecting to the cars loom or to a VTECFROG harness?

The ECT Mod is pretty straight forward. I'm sure that even with the sensor ground connected to the same point as the power ground you would still get a reaction, it just may not be accurate. Assuming the power connections are good (do you get a response from the LED) then I would double check the ECT sensor connection. Make sure you have the correct wire.

If you're sure all connections are correct then I would suggest returning to Modifry. He's very good about that sort of thing.

 

i'm connecting it to the frog harness.. for an EMS.

i was pretty carful about locating the right wires... i even strip the wires cause the taps were having some trouble getting thru the harness...

The LED flashes ...

If you power cycle the car to igniriotn.. there is only 1 light.

if you drive the car to warm it up.. then do the power cycle trick.. i get either 4 or 3 bars.. ( depending )...
then it cycles itself back down to only showing 1 light...
kinda wierd...

 

Have you tried a multimeter on the ECT signal? If should vary with temp in between 0 and 5V. If you can confirm that and the ECT Mod is still not functioning then I'd say send it back. Not sure where Modifry is, but I don't think he has retired to a small island in the Bahamas on the proceeds.

 

Ok,

I finally configured this laptop to communicate w/ the EMS. And It got me thinking (DANGER! DANGER!).

Why is it that the ECT requires different settings for the EMS and opposed to the stock ECU?

The ECT driver 'jacks into' the temp sensor 'directly' doesn't it? If so, the voltages would be the 'same' regardless of ECU type.

Now then, if you had .. a mugen thermostat/spoon thermostat... then you'd be getting different voltages ( I think ), because their function is to 'trick' the stock ECU into initiating a 'cooling' cycle at a lower temperature.

I'm theorizing this b/c.. when i was monitoring the voltages... and it was only cursory cause i was driving.. I haven't fully figured out data logging yet... it looked like the 'stock' ecu voltage/temp guidelines...

Anyone counter this?

 

[QUOTE=DaWorm,Mar 3 2005, 10:38 AM] Why is it that the ECT requires different settings for the EMS and opposed to the stock ECU?

 

Yeah, I'm lost on that one. The voltage from the sensor shouldn't change regardless of ECU. The ECT Mod taps this level and outputs a pulse to the instrument cluster accordingly. You cut the wire from the ECU to the cluster so it has no effect on output.

I must read back through the thread and se eif I can find where Modifry explained the difference.

 

Ok...
Well I hooked into my EMS, set up a paramter screen and put Coolant Temp Voltage and Collant Temp .

What I found is that.. the voltage and temps for the EMS more closely modeled the OEM paramters than the EMS paramters ( as posted on the website..)

I couldn't get to the 'high temps' like 220 and 235 ... but I extrapolated based on the voltages that I was seeing for the 'lower' values.

After much soul searching.. I reprogrammed the driver as instructed....

Inshort... I no longer have the one bar issue!!! The gauge appears to be working!!!!

Most of the time.. I sit on 3 bars... and if I cut the throttle after a drive.. it pops up to 4 bars for a bit... Which is reasonably consistent with what I've been reading on my gaugetech before i dropped it.

Anyways.. its working!
Thanks modifry.. i feel more settled KNOWING that the car isn't burning up rather than just waiting for the EMS to throw a CEL at high temp...

 

Sorry I've been out of touch for a while - my work laptop bit the dust 2 weeks ago and I still don't have it back. To be "legal" as far as my company's IT dept is concerned and keep personal stuff off the laptop, I had been using a separate hard drive for all my personal files. But without a laptop to plug it into, I ain't got squat. Result - new Dell laptop will be delivered next week, just for Modifry. In the meantime I'm working off a set of old backup files loaded onto my wife's home PC, which isn't very convenient when I'm travelling, but it's better than nothing.

Da Worm - Glad you got it figured out, you must have been the "lucky" customer to get the stock ECT by accident, for which I apologize sincerly. Didn't mean to cause you so much grief.

ECT Sales - I'm over 20 units ordered now, so I won't complain any more.

ECT for an '04 - I still plan to do this, just need to grab a local owner and spend a few hours one afternoon taking some measurements on his car. Hopefully it's close enough to the previous year's operation that I can just change the software to get it to work.

Sensor voltages & different ECU's Here's the deal. The sensor is the same in both cases, and in both cases it connects from ground to the ECU input, and through the ECU to +5v. But what's there is a difference. In the stock ECU the sensor input goes through a 1.5k resistor to +5v, but in AEM it goes through a 2.2k resistor.

As an example, let's say the sensor has a resistance of 1.5k at 100 degrees. That means (on a stock ECU) that there is 3k from +5 to ground (1.5k for the sensor plus 1.5k for the resistor in the ECU). Good 'ole Ohm's Law kicks in here and says the total voltge will be divided up across the resistors in proportion to each resistor's percentage of the total resistance. So 1.5k/3k = .5 and .5 x 5v = 2.5v. Result - at 100 degrees the sensor voltage is 2.5v. ( I made these numbers up, don't think this is the real voltage for 100 degrees).

Now let's see what happens with the AEM ECU. It has a 2.2k resistor to +5v, so at a sensor temp of 100 degrees the total resistance is now 3.7k (1.5k + 2.2k). Doing the math, 1.5k/3.7k = .405 and .405 x 5v = 2.02v. So on an AEM, at 100 degrees, the sensor voltage is 2.02v. That's a lot different than the 2.5v we get with the stock ECM, and explains why Da Worm's module didn't work right till he re-programmed it. The module was expecting 2.5v but was only seeing 2.02, so it always displayed a low reading on the gauge. After he programmed it with the correct voltage levels for the AEM application the gauge started displaying correct readings.

If I was AEM I would have never used 2.2k, I'd have picked something like 1k or less. The stock system provides a voltage range of 0-1v for normal* engine temperatures, but because of the different resistor the AEM reduces that range to 0-.65v, providing less precision in the measurement. Makes no sense to me.



*Cold temps do generate voltages above 1v but who cares? Is it important to know the difference between 10 and 30 degrees? No. But it IS important to be able to tell 210 from 230, so in my opinion you need more accuracy and precision at the upper end of the scale even if it causes you to lose some resolution at the low end.

.[B]

 

Well, finally got mine installed this weekend and saw the temp gauge work for the first time in over a year! I felt like I was driving a new car.

Thanks again, modifry.