Limp Mode and without USB cable connected

K-Series Programmable ECU installation questions / support issues
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_Shift_
Posts: 6
Joined: Tue Nov 23, 2010 12:37 pm

Limp Mode and without USB cable connected

Post by _Shift_ »

Hello,

I searched through the forum to find a solution but wasn't lucky. Some of the threads were similar but not what I have been experiencing during a recent race event. The CEL will come on start and during idle and would be in limp mode. Battery voltage is fine have checked at ecu during cranking... have encounter this in the past... but i remember error code showing in window.... During these limp modes when I try to get the error code none is shown on the Error Codes Window. I only used the kmanager software to check codes. (K manager Version 1.4.1)

I then tried it on another car and the same thing would happen. Same type of harness (JDM-R) and the other vehicle is kpro equipped as well both running maps based on the the same starting base file. This would suggest it does not have anything to do with the cal file, harness, ground, since they are identically built. ECU is the same type (PRC). Don't have the serials at the moment.

Anyways this limp mode thing kept popping up during the week every time we needed to stat up the car.... but did not happen previously. I tried clearing ecu and reloading cal file but did not help.

I noticed the problem going away when I stop and restart the car with my laptop plugged in but continue to get limp mode when i disconnect my laptop. So for testing purposes I tried it with just the USB cable plugged in and the other end disconnected from the laptop. With just the USB cable attached it starts up fine. Once running it would continue to run fine even after unplugging the USB cable from the ECU.

Turn off the car, unplug the USB cable and the start up the car again you immediately go to limp and get the engine light. Plug it back in and it starts up normal. I did not leave the cable plugged in while the car was out on the track since I don't believe it the map not something with the car. Everything runs fine after the initial startup. And since this was tested on 2 cars and 2 ECUs, it kind of obvious its something with the particular ECU. Nothing seems to be wrong with the board etc when we took off the cover, but have not gotten a chance to look at it any closer.

I've asked a local dealer about it and he have never heard of anything like this. Reading through the forum it seems that several members out there have had similar problems.... but I was wondering if anyone tried just plugging in the USB cable and no laptop?

Bad insulation on the ECU cover? Suggestions on which direction to look would be appreciated.
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Spunkster
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Post by Spunkster »

What is the USB cable plugged into?
_Shift_
Posts: 6
Joined: Tue Nov 23, 2010 12:37 pm

Post by _Shift_ »

Sorry for the late reply. The other end of USB cable is not connected to anything. Any ideas?
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Spunkster
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Posts: 23881
Joined: Fri Sep 20, 2002 5:06 pm
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Post by Spunkster »

Have you broken something inside the USB connector?
_Shift_
Posts: 6
Joined: Tue Nov 23, 2010 12:37 pm

Post by _Shift_ »

No the usb connector isn't broken. Otherwise I would not have been able to communicate with the Kpro. And no the USB Cable isn't the problem, why should it be.

Anyways gotten to take a look at the boards more closely. It seems that the soldering of the boards were kind of messy causing unintentional contact with some of the closely placed pins. Cleaned it up and now the units working fine.

Tested 3 days on the car w/o any hiccups.
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