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Discussion Starter · #1 ·
After installing my tuned PCM my TB check engine light has come on twice now. Both times were at speed around 60mph on the freeway. The code that came up read "transmission comp slipping." I called Kelly at PCMforless and they haven't heard of this happening. Would anyone know why this code is now pulling up on the TB? Never had it before, and they almost have to be related being something with the powertrain and a PCM tune... Any help from members or Kelly or Alvin would be much appreciated.
 

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transmission comp slipping usually refers to a problem with the torque converter slipping or not locking up
 

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i am not sure. the problem could have been there but with a stock tune the computer didnt notice it because of the torque managment. and now with the firmer shifts and such it recognizes the problem
 

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Discussion Starter · #5 ·
i am not sure. the problem could have been there but with a stock tune the computer didnt notice it because of the torque managment. and now with the firmer ****s and such it recognizes the problem
:ugh: kind of what I was worried about either way. I like the new tune and the shifts. I really haven't noticed much though as of power and acceleration gains. hopefully I don't have to send it back to de-tune or dumb down the current tune. I don't want the tune to cause a problem, but I want the tune. I don't know what to do or think right now. :worried:
 

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i would just wait and see what they say. but i hope it works out in the end for you
 

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Discussion Starter · #8 ·
p0894

So Peterson Chevrolet wont tell me what the Transmission Component Slipping code means unless I shell out $89.99. Gotta love the stealership... The exact code coming up in the scan-tool is P0894. PCMforless is going to send me core with a flash tune done to it. I think I'll try the shift firmness @ 1 instead of 2 to see if this stops the code from coming up again. If anyone has any other ideas on why this code is now appearing that would be great. Any help or incite is much appreciated. thank you.
 

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Discussion Starter · #9 ·
currently doing security relearn on new core

hopefully this resolves the issues I was having with the P0894 code... Yesterday a new code came up also... I hope it resolves this one too, new code was Torque converter code/clutch position stuck. I wrote down the code but cant find it... I'll need to do a CASE relearn at the dealership anyway so I'll have them check it out. Will they be able to do a CASE relearn, also check the codes coming up and fixing the issues without erasing my new tune? I've spent $200 in this tune currently and would hate for it to just disappear... :worried:
 

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Discussion Starter · #11 ·
If they mess up and erase it, kelly at pcmforless would be glad to put it back in for you so no worries.
Yes that is what I've heard. Shipping will still be a :x and will have to do another CASE relearn... But, so far so good! The TB is running better than it did after the 1st tune (which is weird because it was the original PCM and not a core), The CEL hasn't come on yet so hopefully the new tune fixed the 1st set of issues (probably not showing because of the security relearn?), but since there is no CEL, will a dealership still do the CASE relearn? Or will they say that it doesn't need one since there is no CEL?
 

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Yes that is what I've heard. Shipping will still be a :x and will have to do another CASE relearn... But, so far so good! The TB is running better than it did after the 1st tune (which is weird because it was the original PCM and not a core), The CEL hasn't come on yet so hopefully the new tune fixed the 1st set of issues (probably not showing because of the security relearn?), but since there is no CEL, will a dealership still do the CASE relearn? Or will they say that it doesn't need one since there is no CEL?
You dont need the CEL on for the dealership to do the CASE relearn.
 

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Discussion Starter · #13 ·
You dont need the CEL on for the dealership to do the CASE relearn.
For some reason unknown to me, the TB didn't need the CASE relearn done. I brought it in today, we hooked up the tech 2, and the only code showing was that I overrode the security (security relearn). which passed, but did show a code, no CEL and it passed anyway. We even checked the specific code P0315 and it showed crank angle sensor or something of the source all passed. A double checked with the tech, and he said that there is nothing to relearn if it is showing passing in the tech 2 scanner. It is now driving great, so i'll keep my fingers crossed and hope nothing backfires on me or the TB. but so far so good!
 

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I wish I would have seen this thread! I had the exact same problem my first trip down to St. George after having the lift and tires put on. I drove 250 miles with the CEL on because I couldn't turn back.

The very next morning I got the TB into a dealership down there. They went through the valve body and checked all valves and solenoids, replaced fluid, filter, cleaned the throttle body, just basically inspected everything. They concluded that nothing was wrong, but the TC may not be dealing with the stress of the larger tires very well. It didn't need to be replaced at the time, but if it happened again that would be the repair. $700 and 2 days later I was back on the road and haven't had the problem since.

How is your speedometer reading with the new tires?
 

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Sometimes older weaker transmissions might give this code after one of our tunes because the truck has more power and they shifts are trying to happen in a quicker fashion. There are also quite a few times where this code will trip, you clear it and it never comes back again.

Just keep us updated. Also double check your trans fluid level (check owners manual for proper procedure). The new power/shift firmness might be showing a problem you didn't notice on the stock tune.
 

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Sometimes older weaker transmissions might give this code after one of our tunes because the truck has more power and they shifts are trying to happen in a quicker fashion. There are also quite a few times where this code will trip, you clear it and it never comes back again.

Just keep us updated. Also double check your trans fluid level (check owners manual for proper procedure). The new power/shift firmness might be showing a problem you didn't notice on the stock tune.
My TB has about 38k miles (6k after the lift, larger tires, and tune). I have only seen the P0894 code once and the P0741 twice.

The second time for the P0741 I was able to clear the code with my Scan Gauge and everything went back to normal.

The code only appears when the transmission fluid temperature gets up around 230 degrees. 1-2 shift becomes very harsh as well. After the fluid temp gets back down to around 200-210 degrees everything works fine again.

Looking into a Transmission Cooler Kit to see if this will help. After that if the problem persists, I will replace the TC with a heavier duty unit. Eventually the transmission will be upgraded with heavier duty internals and clutches.
 

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I will agree with Shawn. I however don't have a scangauge, so I don't know the exact circumstances where the issues are happening. It seems the harsh 1>2 shift comes after being on the interstate for over 15 minutes or so and when the temp is above 75 or 80. I had my lift and tires on for 20k miles before the tune, and never had an issue. As soon as I installed the tune, I saw the codes and the shift issue. I have seen both P0894 and P0741.

Do you boost the line pressure in the Trans in order to firm up the shifts? If so, that would account for why the transmission temperature is heating up more, right? With higher pressure comes higher temperature.

Another interesting issue... the TCC seems to unlock when at highway speeds as soon as any petal pressure is applied. I assume this has something to do with the lower rpm that the larger tires create. If we were to reprogram again, is there anything that could be done to keep it locked a little longer?

Sorry for the questions, it seems Shawn and I are experiencing very similar issues. Thanks for your continuing customer support. :thumbsup:
 

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Most trans builders recommend higher line pressure so that the clutches are slipping into engagement. The slipping clutches generate more heat than more line pressure.

I would seriously recommend a transmission cooler. I cringe at tranny temps above 200 degrees. At 230 you are likely going to see a seriously shortened transmission life.
 
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