iNVAR Posted April 1, 2013 Share Posted April 1, 2013 Have you tried a different laptop? Link to comment Share on other sites More sharing options...
Cone_Killer Posted April 3, 2013 Author Share Posted April 3, 2013 Its an ecu issue. It does it with SD card logging. Instead of cutting out though, it just repeats the same line of data over and over. Link to comment Share on other sites More sharing options...
iNVAR Posted April 3, 2013 Share Posted April 3, 2013 Damn..... hmmmm that's... irritating to say the least. Link to comment Share on other sites More sharing options...
RallyMachine Posted April 3, 2013 Share Posted April 3, 2013 I was looking through one of the romraider.com threads posted by invar and somebody said that Subaru used a chassis ground for the OBD port instead of a signal ground. Could the port possibly be picking up interference from increased output at WOT from the chassis ground? Would there be any benefit to regrounding the OBD port to the negative battery terminal? Link to comment Share on other sites More sharing options...
Cone_Killer Posted April 4, 2013 Author Share Posted April 4, 2013 ^ I thought it was the other way around. Link to comment Share on other sites More sharing options...
RallyMachine Posted April 4, 2013 Share Posted April 4, 2013 I'm not sure...just going off what I read in the thread. It wouldn't be hard to test both, but my biggest issue is hacking into the OBD port wiring Does anyone know how hard it would be to change out the ECU? I found my metal tag for reprogramming, but after that is done by a Subaru dealership, is it just plug and play? Link to comment Share on other sites More sharing options...
iNVAR Posted April 4, 2013 Share Posted April 4, 2013 Changing out the ECU requires reprogramming all of your keys also. Link to comment Share on other sites More sharing options...
spec.B Dream Posted April 4, 2013 Share Posted April 4, 2013 Does testing CCA really give a good picture of how the battery behaves under WOT when the alternator cuts out? All I know is this issue drove me crazy for months and went away when I replaced the battery. Link to comment Share on other sites More sharing options...
Cone_Killer Posted April 4, 2013 Author Share Posted April 4, 2013 I did some WOT battery voltage logging earlier in the thread. Everything was pretty much the same. Link to comment Share on other sites More sharing options...
RallyMachine Posted April 4, 2013 Share Posted April 4, 2013 Can anyone actually confirm that the alternator cuts out? I had a source tell me that it does not. Plus, if the battery had weak output at WOT wouldn't other symptoms be noticed like dimming of dash, headlights, radio static, etc.? Link to comment Share on other sites More sharing options...
Strizzy Posted April 4, 2013 Share Posted April 4, 2013 Subaru used a chassis ground instead of a direct ground signal from the ECU, to the OBD port. In theory, it should work just fine, but there can be too much interference from other devices, and the ECU hiccups and drops communication with the logger. I recently just had to swap out my ECU again because of some dumb things on my part. I swapped back to my original ECU and found out I had to reprogram it again to work with my keys. But since that ECU had given me trouble in the past, I have another one on order. I have access to a SSM3, so reprogramming the ECU is no problem for me. Just make sure you bring ALL of your keys, including your valet key, when you get the ECU reprogrammed. As I mentioned to the OP previously in a PM, what improved my logging problem the most was adding a .01μF ceramic capacitor between the wires for pin5 & pin7 of the OBD plug. This helped filter the electrical noise and enabled me to log at least one WOT pull after plugging in my Tactrix to the OBD port. My bad luck build Link to comment Share on other sites More sharing options...
RallyMachine Posted April 4, 2013 Share Posted April 4, 2013 ^^So you were able to do a WOT pull after the capacitor, but could you consistently get a complete log, even if you had to try a couple times? Also, did your new ecu help the logging issue at all or was it strictly the capacitor? Would there be any benefit to grounding the port straight to the battery instead of to the chassis? Link to comment Share on other sites More sharing options...
Strizzy Posted April 4, 2013 Share Posted April 4, 2013 I was able to get a complete WOT log on the first pull after plugging in the tactrix. To get another log, I would have to turn off the car, unplug the tactrix, turn it back on, plug in the tractrix, restart RomRaider, then do my next pull. There wouldn't be a benefit to grounding directly to the battery, as the problem is that the ECU signal ground is grounded to the chassis and the OBD signal ground pin is coming from the chassis. You would have to make a direct connection from the ECU signal ground to the OBD port's signal ground pin. My bad luck build Link to comment Share on other sites More sharing options...
Strizzy Posted April 4, 2013 Share Posted April 4, 2013 I spent a good two months trying to figure out the problem and found it easier to just replace the ECU with a used one I found on car-part.com My bad luck build Link to comment Share on other sites More sharing options...
RallyMachine Posted April 4, 2013 Share Posted April 4, 2013 So do you think that you could have just put the capacitor on the 2 wires instead of changing out the ecu, or was it an internal problem with the ecu? Edit: I'm not positive, but it looks like there is a signal ground as well as a chassis ground on the OBD port. Since the signal ground is also grounded to the chassis, maybe this is causing a ground loop under certain engine loads? Just think out loud...or in text Link to comment Share on other sites More sharing options...
Strizzy Posted April 4, 2013 Share Posted April 4, 2013 I tried the capacitor, but it was too frustrating to log. My setup is FAR from stock and just doing WOT logs for tuning wasn't enough. I didn't want to do the whole stop/restart procedure every time I was trying to tune. Replacing the ECU makes it seem it was an internal issue with the old ECU, since everything works flawlessly after I replaced it. My bad luck build Link to comment Share on other sites More sharing options...
Cone_Killer Posted April 5, 2013 Author Share Posted April 5, 2013 I wonder what the odds of getting another bad ecu are? Link to comment Share on other sites More sharing options...
RallyMachine Posted April 5, 2013 Share Posted April 5, 2013 Maybe the ecu going bad is a result of previous tuning? Has anyone ever had this problem on a stock car? Link to comment Share on other sites More sharing options...
iNVAR Posted April 5, 2013 Share Posted April 5, 2013 ECU doesn't just go bad from the tune, not in this fashion. Link to comment Share on other sites More sharing options...
Cone_Killer Posted April 5, 2013 Author Share Posted April 5, 2013 My car was stock with this problem. Link to comment Share on other sites More sharing options...
RallyMachine Posted April 7, 2013 Share Posted April 7, 2013 SUCCESS!!! The .01uf capacitor did the trick! Thanks for the help guys! Link to comment Share on other sites More sharing options...
uncle humjaba Posted April 10, 2013 Share Posted April 10, 2013 How exactly did you put that capacitor in there? Trip the wires and solder it in? Link to comment Share on other sites More sharing options...
RallyMachine Posted April 10, 2013 Share Posted April 10, 2013 I just jammed the capacitor wire into the back of the port with the wires that needed to be connected. Wires 5 and 7. No cutting/splicing required. I used a 50V capacitor, YMMV Link to comment Share on other sites More sharing options...
uncle humjaba Posted April 11, 2013 Share Posted April 11, 2013 I may give that a shot as I have access to a cabinet full of capacitors. The vag-com cable doesn't work (cuts out at ~4000rpm) but my friend's Tactrix 1.3 does. Following this pinout? http://www.ls1tech.com/forums/attachments/conversions-hybrids/30711-who-has-modified-their-own-ls1-harness-obd-ii_pinout.jpg Link to comment Share on other sites More sharing options...
RallyMachine Posted April 11, 2013 Share Posted April 11, 2013 Sounds like yours might be an issue with the cable itself.... But yes I followed that pinout. Don't pay attention to the red terminals, just connect pins 5 and 7 (there should be wires in them already). Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.