Hello I have an early 99 f350 dually 4X4 with a 4R100. The TCC dosnt engage in third when trans goes to 4th it will lock then unlock right away. Then randomly it works proper locks in 3 & 4th everything is good. All brake lights work has new VSS in the diff ( to fix abs light) also new brake peddle switch. I have the cts2 showing gear & lock once in a while the gear will flash P then back to 4 it is very fast. Where should I look next TIA

 

first off, do not go by the Edge CTS, there's a huge delay.
Factory tuning and most tunes go 1,2,3, TC lock/ OD. sometimes the TC will stay locked during downshifting to a point.
If the shifting all seems fine, then I wouldn't worry about it. You can also read for codes but I think the OD light will flash at you when there's an issue

 

the OD light dosnt flash. But it works fine sometimes then other times in OD the TC locks then right away unlocks

 

I can also verify this, my Butt Dyno tells me when the TC locks up, and the CTS-3 takes a good bit of time to catch up, if you will read the Specifications on the CTS, it tells you about the Time Delay, and that you can modify it to some extent.

 

If your gear display is flashing P while in Drive then I would look at the neutral switch. Maybe the PCM is killing the LU due to seeing it not in drive.

Otherwise I’d probably start with the brake light switch. It’s new and possibly glitchy. I believe some tuning goes LU off when it sees the brakes. If it’s consistent, maybe take a drive somewhere secluded with the switch disconnected to see if it changes anything.

 

Jason I was thinking the same thing. When i wiggle the gear shift that dosnt do anything weired. Got the solus edge scanner on and map psi follows boost pressure but MAP hrz stays zero the whole time.

 

You will not get a frequency (Hz) reading. The 99-up 7.3 uses a voltage return to determine MAP.

Early 1999s through model year 2000 used calibrations that do not natively apply the torque converter clutch in 3rd gear under light to moderate acceleration.

I'm not inferring that there's not an issue here, but accelerator pedal position plays a huge role in 3rd gear converter clutch apply and 3-4 upshifting characteristics for these 3 model years.......and they SUCK.

 

I'm pretty sure I remember my PCM being XLE4, and I like the converter clutch staying locked when I'm braking in OD. I don't find anything terribly bad about the shift strategy, but maybe there are things I've never paid attention to. What is it that you think sucks about the 3-4 shift?

 

I never said anything about the torque converter clutch in relationship to the brake pedal being depressed. One redeeming quality of the XLEx family is that the brake position doesn't dictate converter clutch operation.

The comments I made were specific to the upshifting characteristics of the E99-2000 calibrations. Factory calibrations apply the torque converter clutch and perform the 3-4 upshift at the same time under light/moderate acceleration at 43-50 MPH. It's stupid and annoying.

 

Cleatus, are you saying for the OP’s truck that the brake switch does not impact TC LU?

Not questioning if you’re correct, only questioning the master about its function so I can understand better.

If I understood you right, then doing the switch test I suggested would be pointless.

 

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No, I know you didn't say anything about it. I was just saying it's something I like about my E99 calibration.

 

I am no "master". I'm no less infallable than anybody else. How obsessive about things regarding certain subjects? All of it.
It depends on the calibration. In the grand scheme of things, Ford's 7.3L Powerstroke torque converter clutch strategies have gone full circle a couple of times from 1995-2003. From bad to ok then back to abysmal to as good as it got. I run an XLE4 in my 2000 2WD - because I can and now I'm too lazy to go back to a period-correct one and the shifting is WAY less dependent on accelerator pedal rate of change or vehicle acceleration since the DPC-4XX hardware makes shift scheduling changes based on rate of change and I have yet to figure out how to make it like the 1995-1997 vehicles that do WHAT they're told WHEN they're told to do it.

Here are a couple of specific examples:

XLE4 (E99):

• Upshifting with light/moderate acceleration - 1, 2, 3, 4 and instant torque converter clutch apply at 43-50 MPH.
• Upshifting with moderate or above acceleration - 1, 2, 3, TCC apply, 4. (This is REALLY HARD to attain....perfect balance required.)
• Upshifting with towing or really heavy foot - 1, 2, TCC, 3rd (TCC remains applied), 4.

To me (and as indicated in the tuning), the 2nd gear TCC apply under heavy load is WAYYYY too early (like 30-35% too early). It had been corrected in later calibrations to only apply at 50+%.
If the transmission control switch (TCS or overdrive "OFF" switch) is depressed in 4th or after the torque converter clutch has been applied for that upshift cycle, it will remain applied for 30+ seconds on deceleration regardless of brake on off (BOO) input to the PCM. The torque converter clutch and coast clutch will remain applied in 3rd gear above 35-ish MPH with the overdrive "OFF". Once the torque converter clutch has been released (but overdrive left "OFF"), the torque converter clutch will reapply in 3rd once the minimum apply speed has been reached (actual value escapes me at the moment). If the 4th gear is no longer inhibited by the TCS after TCC release, then the normal shift pattern resumes.

The torque converter clutch strategy for something like an MNM0/1 (2000 MY) releases the torque converter clutch as soon as the brake pedal is depressed in 3rd or 4th gear. The TCC is also released after about 12 seconds of deceleration if the BOO input to the PCM isn't activated (which acts very much like all pre-1997 OBS calibrations.....DUMB). I can't recall the upshift pattern at the moment - maybe an experiment for spring. This calibration is where I get the data I fight Mark Kovalsky about regarding effectiveness of the torque converter clutch for engine braking (and he claims 10%). There are some steep hills around here so it's easy to test engine braking effectiveness (which is never much with a diesel anyway) and to watch data and see that the transmission is in 3rd (TCS activated so the coast clutch is applied) and then coast down a long steep grade. When speed can either be maintained (or lost) and then the TCC releases (and the coast clutch remains applied) and speed increases dramatically....well....that's pretty definitive to me.

I think that's about all I want to type out for now. Lunchtime is over! BACK TO WORK!

 

Thank you!

 

I got the lap top hooked up with fourscan on it. Accelerator position starts @idle is11.91% at WOT it will change between 74.71 74.81. My choice for a new switch only local is BWD automotive or Techsmart. Has anyone used these?

 

That seems pretty normal.