USB Loses Link When On Battery

[ReZZeX]

Well I checked through the forum and noticed a few other people had problems with USB connectivity between K-Pro ECU and their Laptop with K-Manager.

My car is an Acura RSX Type-S (K20A2) with Injen CAI, Hondata IMG, and K-Pro, which I installed all at the same time. I'm using the latest version of K-Manager and USB drivers. Also, I just got K-Pro less then a month ago, so it's been the latest version, but I also checked for updates.

So this is what?s happening. I originally setup my K-Pro using a desktop computer with USB 1.1. I first uploaded k20a2-rsx-coldair.kal. I made a few modifications to the base map, changing the red line from 8600 to 8400, and turning on the immobilizer. I then data logged the car for about 15 minutes letting the car idle with no problems. I then reved the car a little and brought the RPM?s up to about 2500 give or take, then playing around looking at all the sensors for another 15 minutes. So for about half an hour the ECU had connectivity with the desktop computer.

So since I didn?t get my new Laptop yet, I went to a friend?s house about 2 weeks later after driving the car around without data logging it again since. I took his laptop, which was a Dell with Intel Centrino and USB 2.0. I plugged in the USB cable from the ECU to the laptop, obviously I installed KManager and the USB drivers, and I had connectivity with the ECU on the laptop. I began to datalog with the key turned on, but without the car started. I then started the car and everything was data logging like it was before on the desktop computer. So I began to drive up the street, took a left hand turn and then I looked back down at the laptop when I got to the end of that street. It wasn?t more then a minute and the data logging stopped. So I was checking out the computer, it still saw the K-Pro connected under Device Manager > Universal Serial Bus controllers. So I unplugged the USB cable from the back of the laptop, and then plugged it back in. K-Manager then allowed me to press the datalogging button. So I figured I was good, and then less then 30 seconds later I lost the link between the ECU and laptop. Again I would unplug, and plug the USB cable back in the laptop, and like 10 seconds later I would loose connection. This would just continue to happen. The times it had connectivity with the laptop was all random, usually less time the more times I would unplug and plug the USB cable in. When I first would start the car it would generally have the longest connectivity. I gave up; I figured it was something to do with USB 2.0, or the laptop.

So I got my new laptop with Intel Centrino and USB 2.0 a few days later, setup mine and I figured I would have no problems. To my surprise the same problem persisted, where I would loose the link between the ECU and Laptop while datalogging, and have to unplug, and plug the USB cable back in to get it to regain the link between the 2.

So I checked the USB connection on the ECU, perfectly fine, I put some extra 8awg copper wires from the IM and the top of the stud on the engine to make sure there was a good ground. Tried datalogging again, and the problem still persisted.

I also checked the BIOS in the laptop, because in some computers you can change between USB 1.1 and 2.0, but there was no option to do so.

I then out of curiousity plugged the laptop in to the power outlet, rather then running off the battery (like the desktop was, since they don?t have batteries). And to my surprise, datalogging worked flawlessly. I let the car idle for about 10 minutes, and revved the car a little, no connectivity problems at all, I never lost the link. I then unplugged the laptop from the power outlet in hope it would work, and it went for a good 2 ? 3 minutes, then all of a sudden it lost the link with the laptop. It continued to have a link much longer then normal on battery. So I?m puzzled.

Two things I was thinking of was since the desktop/laptop were plugged in to a power outlet was it grounded so it did something? Also, when you disconnect the laptop from a power source and it runs on batteries, or moreover a Centrino laptop if that makes a difference, does it cut down the resources allotted to USB while on batteries? Thus, it would not be able to keep up with datalogging, and loses the link? Only other things I could come up with. Hopefully someone has some idea how to resolve this.

Thanks,
Erik

[Hondata]

Some laptops shut down the USB port at times to save power. Check the power saving settings and see if there is anything about the USB.

Many laptops have a poor USB waveform when on batteries (the signal voltage drops from 5V and the slope of the waveform is less). If the signal quality is marginal then on batteries the laptop will lose the USB signal and stop communicating with the ECU.

First check that the engine ground near the injectors is good. Then check the spark plugs are stock. After that, go here and we will send you a new USB cable which will fix the problem.

[ReZZeX]

I went in to device manager and went in to the power management setting for the USB hubs and unchecked the option to ?Allow the computer to turn off this device to save power?. This did not solve the problem.

I called Hondata?s tech support, and I believe I talked to Matt who I explained my problem to. He advised my to make sure the ground was clean and secure, which it is. Then he asked if I have resistor spark plugs, and I have an ?02 RSX Type S with stock plugs in it. He then said is possible that the stock plugs may not have a resistor, which I figured they all would have. So he said the only way to know for sure would be to pull the plug and read them. I will try that and hopefully find out if they plugs have a resistor or not?but I thought all stock plugs had resistors.