Cannot log WOT pulls

[heiche]

fyi - solved the same issue this week. but for me the 0.01uF capacitor didn't help, but 0.1uF seemed to fix it completely! (pins 5 and 7, stripped a little insulation about an inch behind the connector, soldered in the capacitor, and taped it up)

[RallyMachine]

Just a little update with this...

 

I started logging for an e-tune a week or two ago and was still having some issues with data cutting out at WOT (albeit much more minor with the capacitor, things like randomly repeating entries instead of changing values). I replaced the .01uF cap with a .1uF as suggested in the post above^^ and everything appears to be working perfectly after 5 pulls!

[seabass07]

Hmmm. Lazy subscribe. I might give the capacitor a try.

[JMLegacy]

Ok, so my car was cutting out. Tried both cap values, none worked and the 0.1 valued one prevented the cable from flashing.

 

Guess what fixed things?

Fixing an intermittent misfire I had fixed the logging issue!

Not sure what's the correlation.

[seabass07]

What did you do to fix the misfire?

[JMLegacy]

I set out to change my plugs to smaller gaps, when removing one of the plugs i noticed it was cracked!

It was probably leaking current.

[jbean]

I'm going to revive this oldie because I was at my wits end with my AP v3 cutting out all over the place. Couldn't WOT log at all and AP would lose communication with the ECU with boost over 10 PSI in some circumstances. I cleaned my battery terminals, I cleaned the ground just above the transmission, I tried a ferrite bead on the OBD II cable. None of those things worked. This is the one solution that has made it work perfectly and not cut out at all under boost. 0.1uF capacitor on wires 5 and 7 jammed into the back of the OBD II port like RallyMachine says. I would advise anyone having this issue to take this step.

 

Thank you all so much.

[hadvw]

Thanks - will definitely try this!!

[heiche]

Try those couple of different values if necessary, but your results may vary. I found when I posted that over 4 years ago, it solved my logging issue with my 2005 LGT, but I later discovered I couldn't flash my ECU with that capacitor (0.1uF) in place. Just wanted to mention this in case anyone inadvertently introduces this issue.

[hadvw]

Thanks. Are you guys using ceramic/film type caps (the thin ones), or the thicker electrolytic type?

[heiche]

Just a cheap ceramic cap.

[solidxsnake]

I'll chime in here: adding a couple different caps of different values between GND and the +V pins (which I assume are what pin 5 and 7 are on the OBD connector) will help noise power rails and poorly designed electronics (in the AccessPort or Tactrix/VAGCOM cable). For people looking to fix this, try using 0.1, 0.01 and 0.001 uF caps connected between these pins (ideally ceramic or tantalum, not electrolytic). Additionally, try cleaning or replacing your chassis-to-engine ground straps and upgrading your ground cables, as well as making sure your battery terminals are clean and well connected.

 

The underlying issue is a noisy DC voltage rail to the electronics in the logging device, and the extra capacitors add decoupling to the rails to reduce the noise. Better grounds will also help the problem. In my experience, ferrite beads around a USB cable is the least effective method of fixing this issue.

[hadvw]

So, the "noisy grounds" issue makes sense to me. That, or the "ECU drops the OBD port when too busy".

 

For me, the problem is worst when I get a "jolt" of power when it shifts from 1st to 2nd under WOT (when accelerating from a dead stop at a light on the freeway on-ramp, for example - we have those here in NorCal to limit how many people can get on to the freeway per second to try to reduce congestion). Note: stage 3 '05 5EAT + Hexmods F1, so I get a decent kick when it shifts under WOT, but this was already there BEFORE the F1. I noticed this most in BTSSM when trying to log (with my VAG-COM cable + OTG USB cable + Amazon Fire tablet) to diagnose a misfire.

 

Pretty much every time I hit this "jolt" condition, BTSSM will kick out. And I generally have to restart the car and/or restart the tablet - once in a while it will reset itself 5-7 minutes later, but almost never. Have never had a problem flashing - although have had to wiggle the connector of the cable at times for a good connection. That's definitely part of it as well, for me, I think. I've probably connected this cable 50+ times as well as my old APv1 maybe 10-15 times for logging + flashing. Definitely need to push it in a bit to make a connection - any suggestions for a good OBD-2 splitter cable that I can use to reduce this problem? With laptop + VAG-COM, didn't have a problem logging. Would get to 3rd at ~20-30 mph (on-ramp), turn on logging, WOT until I get too scared of CPH . Got enough of a log for my tuner to work with, anyway. But, there's not as much of a jolt when doing it this way, either.

 

I just remembered another symptom, which is the reason for this post: pretty much ever since the car has been quite new (i.e. vf-40, stage 1 or maybe even stage 0 - so long ago I can't be 100% sure anymore), when this jolt hits, say flooring it on the freeway at 50 to pass and it downshifts, my driver's side mirror will jump a bit, as if I hit the adjustment knob. At first I thought it was just an optical illusion, caused by the car pushing me back in the seat, but I'm 95% sure it's actually moving a little under these conditions, at least some of the time. I always thought maybe a pinched wire from the factory, but since everything's hooked up in the same area, seems like I have a particularly noisy ground there, and when it gets really bad, it messes up a lot of things. I also often get the "Ill-05 and Ill-06" issue where the dash dimmer switch acts up just a little without anyone touching it, but that's a lot more random, and doesn't seem related to the jolt.

 

I already have a "grounding kit" (i.e. a few 12-gauge strips connecting various parts of the engine together in the engine bay, all leading to the ground terminal of the battery) from trying to diagnose a hesitation in certain conditions - turned out to be a bad coil pack, which BTSSM helped track down (it showed up under normal driving levels). But it sounds like my under-dash driver-side section needs a better ground. It's possible that my chassis grounds are old/broken - is there a good guide somewhere to finding/checking them? I don't really know where to look. Or is there some ground distribution pin/trace for that part of the electrical system I could direct-connect to the battery (or one of my grounding-strip points) to kind of help the whole area out? I already have a ground strap near the TMIC - wouldn't be that hard to run a wire from there through the grommet I use for my boost gauge.. Just need to know where to connect it.

[TurboQueef]

Good day,

 

I had been fighting this problem for almost a year. Strange as it sounds, replacing the spark plugs completely eliminated it for me.

 

Note: Before finding the spark plug fix I: Replaced alternator, installed filter caps on each OBD-II wire (.01uf and .1uf) installed a 1000uf electrolytic cap on OBD positive lead, confirmed all OBD pins were making good contact to their respective hole, installed a GATES body to ground strap, installed additional ground straps in engine bay and to the ECU and OBD port.

 

Note: Before the fix, as time passed the frequency of accessport disconnecting from the ECU increased and the interference started to affect my Kenwood DDX9903S head unit. At same time AP disconnected, I would hear a loud pop out of the subs and the audio feed into the Kenwood would stop until I re booted it.

 

I spoke with a friend who works in the automotive repair field specializing in electronics.. he has experienced several occurrences where the coil pack could not deliver the energy through the plug (in form of the spark) and the energy produced by the coil pack returned through the positive lead causing "all kinds of he!! to break loose electronically".

 

Well, in my case all is well for over a week now simply by replacing the plugs.

 

Note: I was running DENSO IKH20 Iridium's, now running NGK LFR6A-11

[hadvw]

Good day,

 

I had been fighting this problem for almost a year. Strange as it sounds, replacing the spark plugs completely eliminated it for me.

 

 

...

 

 

Note: I was running DENSO IKH20 Iridium's, now running NGK LFR6A-11

 

 

Thanks. I *JUST* learned of the same suggestion from here:

 

 

 

https://legacygt.com/forums/showthread.php/subaru-legacy-gt-05-09-accessport-screen-flicker-wot-fixed-277899.html?t=277899&highlight=ngk+4212

 

 

(and here is another post: https://legacygt.com/forums/showthread.php/accessport-screen-flicker-during-wot-245247p2.html?highlight=ngk+4212)

 

 

The sooner this information gets out, the better, IMHO.

 

 

I've already ordered NGK 4212s (ILFR6G-E), just waiting to get them installed.