Here is the tune (essentially stock, slightly decreased shift times (10% quicker), increased shift pressure (7%), decreased torque reduction (15%)). The rest is factory stock parameters.
06DmaxVanTCM-01.ctd
Tune and Log files
Here is the tune (essentially stock, slightly decreased shift times (10% quicker), increased shift pressure (7%), decreased torque reduction (15%)). The rest is factory stock parameters.
06DmaxVanTCM-01.ctd
Here is one of the two datalogs from yesterday.E35_0009.efi
Appears that there is a size limit for uploaded files? The other is slightly over 2MB.
- I don't know about the TCC brake switch. Is this the same as the brake switch on the pedal that turns the brake lights on, or something different? I can't find a PID for TSTATE in V8 BBX...Originally Posted by joecar
- I don't have ABS in the van anymore. I removed it completely and replumbed when I converted it to 4wd. I will say that this all started occuring immediately after working on the slip yoke/u-joint. I replaced the slip yoke and a u-joint as I was getting a vibration from my d-shaft. May be purely coincidence. I still have a vibration and need to investigate further. I drove in 3rd gear today for logging, up to 70+ mph, and it felt much smoother than yesterday when I was in 4th gear. Need to reconfirm this by driving again...it was after the fact that I realized it.
- I don't notice any misfires while driving, and am not getting any codes. Being a D'max, how would I check for misfires more thoroughly?
I also can't seem to find GM.TCCMODE in V8 BBX. I am looking in E35A and T42.
I was logging TIS and TOS, sorry I didn't plot them. The data should be in the logs currently.
Throttle position...doesn't respond either. I was logging TP, and it didn't work. I can't find GM.ETCTP.
I don't understand why V7.5 has so many PIDs but none seem to work for the TCM. V8 doesn't seem to have the same PIDs available. What am I doing wrong? I'd like to be logging the right stuff...
THANK YOU!!!
Had a chance to do a quick test drive. First datalog is while transmission is in 3rd gear (mostly, I did shift to 4th manually a couple times, but overall it was 3rd- see data current gear). I happened to log TSTATE3, which ends up is a bunch high idle switch states, etc. I do have a high idle switch installed (GM parts plugged into GM factory harness, new switch as of a few months ago). Why does the switch bounce around on/off? Strange. I assure you I was not playing with it while driving. I also don't understand what's going on with the brake apply, etc PIDs.
I then shifted to D4 and came back. Same crazy High Idle Switch crap. Hmmm...
Could it be that a vibration is making the switch contacts bounce in the High Idle switch? Maybe I need to disconnect the switch and see if it fixes the issue. Seems silly, but in general I'm not opposed to trying stuff like this. I do have a small vib in the driveline right now that needs sorting out. Not sure what that's all about.
Edit: I did confirm that the High Idle switch PID responds when I press the switch on the dash.
Any other suggestions? There are a lot of PIDs in the data logs. Not sure what all of them are, wanted to record as much as seemed to make sense.
THANK YOU!!!
E35_0013.efi
E35_0014.efi
Last edited by jlane330; August 30th, 2016 at 03:50 PM.
Sorry to overwhelm with data here, and possibly dumb posts. This High Idle switch stuff is strange. It appears to be semi-correlated with engine RPM or torque, no? Almost appears that if the torque exceeds a level, or the RPM hits a level, it sets the high idle switch. No idea how this might affect the transmission lock-up or slipping, if at all, but strange none-the-less.
I left the horizontal cursor at the crossover of point where RPM = High Idle (mostly):
Last edited by jlane330; August 30th, 2016 at 04:00 PM.
This log shows (on V7 scantool Data tab):
1. TCC Control (i.e. PWM) Solenoid Short to Power Test: failed.
2. TCC Enable Short to Power Test: failed (this is for 4L60E/65E/70E only, not used for 4L80E/85E).
3. Trans Line Pressure Short to Power Test: failed.
I don't know if those are meaningful, but you may need to check/test the wiring for 1 and 3.
Also, I see that the pid GM.TPS shows 99.6% always... this is a problem.
BTW: when TCC is locked, the TCCSLIP pid should show zero rpm slip.
High Idle Switch... I'm not familiar with that, what is it and how does it work...?
Good observation. I noticed those too in the logs. When I first started logging and monitored the data via the handheld, everything was a PASS IIRC. I try to look over all the data prior to spending time driving around. Anyway, I don't know what all those mean either. Any ideas?
Yeah, so that clearly does not log throttle position on the D'max. The may have forgotten to remove that PID from the logs I took last night, but there is a PID that does show throttle position. I think it ended up being TP_A IIRC.
That's my assumption too. At least it should be significantly less than what it is right now. Sure seems like the TCC tries to engage but the slip never changes.
High Idle Switch is a physical switch on the dash that I can push and it will kick the idle speed of the engine up to 1200 rpm I believe. I added this when I added the engine drive air compressor, to increase the CFM output. It'll also be handy for charging the batteries a bit better when winching (whenever I get the winch installed...was supposed to be working on that until this trans stuff came up). Anyway, if engaged, High Idle turns off when the brake is depressed or the switch is pressed again.
Quick update:
Still working on diagnosing this. Been a bit of a wait for parts and a pressure test gauge. In the mean time I did wire in a manual switch to lock the converter clutch. Test drove it in both 3rd and 4th and locking the TCC manually with the toggle switch resulted in a VERY slight (maybe 10-20 rpm) drop in rpm, but there was still a lot of slip happening even under light load. Romp on the skinny pedal and slip would jump to hundreds of rpm. I think I can safely say that the TCC is not holding, just not sure why now.
Noticed the other day a new phenomena. Occasionally at idle I hear a buzzing sound coming from the converter/bell housing area. Sounds like a vacuum pump, but it's clearly from the bell housing. It comes and goes, and I assume it could be related to line pressure, the converter or maybe the pump itself. It's pretty loud, and distinct. The buzzing seems to vibrate the seats and floorboards slightly too, enough to be felt.
On the suspicion that it is the converter, I ordered a custom one from Precision Industries (in TN) today. I'll plan on swapping it ASAP and then collect some new data logs with the TCC locked.
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