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Lots of codes being thrown

btsayles

btsayles

Diesel Proficient
Messages
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Location
Wisconsin Rapids
Hey guys, got one for ya I couldn't research myself. I drove the truck yesterday and the torque converter wasn't engauging. I confirmed with GMTD and it threw active code 83 TCC PWM solenoid circuit with 39 TCC stuck off, 68 trans component slipping, 83 TCC PWM solenoid circuit, and 81 2-3 shift solenoid circuit in the historicals. At the same time the cruise control quit working. Anyone have any ideas for me? All of my info is below. ALso I do not have the manual lock up mod. Thanks a lot guys! Hope all is well with everyone!
 
Check the big tranny pass trough conector for oil in it or corroded pins or such.
Check the harnass as well for broke wires
Thouroughly check the engine ground at the dipstick tube(check that first)

Is oil level OK?
Is the oil still red?
Does it smell burned?
 
Harnesses and pins look fine. Removed ground cluster cleaned all connections and dielectric greased. Checked tranny fluid. I changed the fluid last year. It was new and didn't smell burnt. Nice and red. Test drove and ran codes again. 68 Trans component slipping and 83 TCC PWM solenoid circuit along with the historicals stored in earlier post. Still no tcc lock up.
 
It could be that youre not building enough pressure. The pressure control solenoid (or force motor) is a common issue and lack of pressure will lead to slipping, late shifts, undefined ratio codes, no pressure for lockup, ect.... The Wester PCM programs from SSD, or just from Westers do not modify tranny parameters, which is annoying, because when they give you more fuel you should get more tranny pressure to prevent tranny issues.

You can find all of the tranny solenoids for $150 online, so if that ends up being the issue, its not a big cost issue. And the sure cure kits are supposed to prevent valve wear on the pressure control and TCC solenoids, two common issues with high mileage 4L80Es.
 
While accelerating you should probably hit at least 60psi on the torque signal pressure, and you can put a pressure gauge in the tranny test port to verify that its actually hitting that.
 
why plug a gauge in? Can't I just watch the screen with the gmtdscan tech? Or could the sensor be malfunctioning? Just took for a test drive. Trans pressure in the 90's. Cruise control is intermittent. Sometime it works and sometimes it doesen't. Force motor running at .74 amps. All trans indications seem to be operating correctly. What is 3-2 PWM solenoid duty cycle? It doesn't seem to be doing anything.
 
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The scanner just shows you the commanded pressure, but no pressure feedback from the tranny, which would be nice. 90psi is the max I believe, so if you have those codes it may be commanding the max pressure, but you have to see with the gauge if you are actually getting it.
 
So the torque signal pressure the scanner is reading is what it is trying to hit and not the actual? That sucks. Guess I'll be fassioning a gauge and line setup. If it comes to it, how hard is it to replace the force motor. Also, where would I find the sure cure kits you are talking about. If I drop the trans pan again so soon, I would like to replace everything I can while I'm in there.
 
Anyone think that maybe theres an issue with the brake switch. Kind of odd that the cruise control and the tcc not locking up all of a sudden at the same time. The brake switch controls both of them doesn't it? The cruise control will be on then just all of a sudden shut off, but the tcc doesn't kick in at all. While on the hwy two days ago, the tcc tried to kick in twice only to kick back into 4th w/o tcc. HMM. How is it to remove that little guy?
 
cc won't work if certain codes stored. also have you checked your CTS in the crossover to verify it's working right? tcc won't lock until the pcm see 170*
 
I would expect a brake switch fault or other faults if something else was actually wrong. I have had them. When it sets these faults its because it actually tried commanding the action and it wouldnt do it. If the engine wasnt hot enough or brake switch was constantly reporting it would not actually try to lock TCC. That doesnt mean all of those solenoids are bad, but they all get the pressure to perform their function from the one solenoid. Or a harness has been messed up and although the PCM sends the signals it isnt getting there.
 
If checking grounds and electrical connections hasnt resolved it, I think the pressure test port check is the next step. The scanner will show you if the brake switch flag is on, as well as engine temp, and tranny temp. The pressure may be lower if you clear the codes and cycle the ignition. If the codes dont come back right away but only after trying to shift into second then it likely wont be max pressure (90psi) until after the codes.

Several pages into this writeup I mention where you can get all of the tranny solenoids and a new internal harness for the 4L80E for $140 and sure cure part number, in the oils section.
http://www.thetruckstop.us/forum/sh...nd-1995-6.5TDs&p=338555&viewfull=1#post338555
 
If I clear the codes and then check the codes right away, they are still there when I use Scan tech. Are the codes not clearing or what?
 
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