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Suddenly no throttle

ok question... just installed the new brake switch and thermostat. got it up to temp which stays at 188-190 acording to GMTDbasic but when I attempt to clear the codes it gives me an error that something went wrong! everything clears out but the one historical code 68- trans component slipping. no codes active. maybe disconnecting the batteries and pressing the brake pedal with the key on for 30 seconds might clear it like on some vehicles to drain the stored voltage in the PCM?
 
Thank you Will and ak diesel driver

I disconnected the batteries and left it for a while. all cleared now. i will do some driving and report back :) now time for me to do some reading on ak diesel driver's cooling fan mod
 
@ak diesel driver I just finished reading the entire thread! all 15 pages and wow! this is definitely the way to go. Many thanks to you and everyone involved for sharing the knowledge and experience in this. I took a bunch of notes while reading :)

I do have a question on the water pump. I am confused as to which pump to choose, I had always thought that I just needed to get a pump for a 97 6.5td and it would be the redesigned one for better and equal flow to both heads. apparently from reading the thread posts, there are some that are and some that aren't. could you point me to which pumps are good and which to absolutely stay away from?
 
The short answer is any spin on water pump will work. The factory water pump for a 99+ was supposed to be the best as far as balanced flow. The problem as I see it is finding a genuine OEM replacement. So many knock offs out there and even alot of AC Delco isn't good anymore in my opinion.
 
My first try would be contact a reseller for AM General. @Twisted Steel Performance Can you sell them? Coming from AM General, that is what is going on new optimizers an obviously into military rigs at this point.

If not him, then try a brick and mortar store near you that you can verify is getting them DIRECTLY from AC Delco.

Are you aware of the bypass restriction fitting? Leroy sells a super nice one. Or diy one like N8in8or did.
 
Update on the code list: replaced the brake switch and installed a 195 deg thermostat yesterday afternoon. cleared all the codes and went for a short test drive making sure the trans was shifting into all gears and TCC lockup was working. Today this evening after work I connected my laptop and no codes... but ... I left it connected watching the ECT and the trans temps and went for a drive.

took a stroll at 60mph down a county road and all was good, ECT ranged between 188 and 194 and trans stayed 150ish so I decided to get up on the highway.

cruised on the highway at about 74 for about 5 miles with the same results. when I went off the exit and into the turn around to go back home I floored it getting back up the on-ramp... that's when the trouble codes came!

trans temp shot up to 165 and I noticed on GMTDbasic the "Current DTC count" was showing 17 !!! I had an "oh $hit moment. I also noticed the truck wouldn't down shift going up the ramp. so I backed off the pedal and took it easy back to the house all the while the trans temp was slowly climbing up to 169-170 by the time I made it to the house. pulled in the driveway and read the codes. there were only two that came up.

39 - TCC stuck "OFF"
78 - wastegate solenoid fault ( still haven't replaced it)

what now? am I looking my trans or my torque converter?
 
Will L. said:
My first try would be contact a reseller for AM General. @Twisted Steel Performance Can you sell them? Coming from AM General, that is what is going on new optimizers an obviously into military rigs at this point.

If not him, then try a brick and mortar store near you that you can verify is getting them DIRECTLY from AC Delco.

Are you aware of the bypass restriction fitting? Leroy sells a super nice one. Or diy one like N8in8or did.
Click to expand...
Confirmed, I can supply true OEM water pumps from GEP, I won't have pricing till after the weekend..

The 4 models I can provide are below


Bolt On CCW HO (serp)---- 4 in stock

Screw On CCW HO (serp)----- 4 in stock

Bolt on CCW STD (serp)---- 2 in stock

Bolt on CW STD (v-belt)---- 2 in stock
 
Did a little research online on the trans code plus figuring that even though the fluid is bright and clean I might as well change it so I ordered the TCC solenoid and the 2-3 shift solenoid with the filter kit for tomorrow. I couldn’t get the 1-2 solenoid so I’ll roll with that and cross my fingers. I’ve done solenoids before on other vehicles and solved issues like this. If this proves as a fail maybe I’ll see a trans shop or call it quits. I’ve put a lot of money into this truck, a rebuilt trans might be the last straw! 😢
 
Update: got the fluid, filter, TCC solenoid, and the 2-3 solenoid replaced. Went for a drive and all went well no codes set. While I was driving I had the laptop monitoring the TCC pwm % and the TCC slippage and noticed that when engaged and cruising slippage stayed at 2-15. A minor press on the accelerator would make the slippage start climbing. It would go up to about 300-400ish before the TCC would disengage. I could also do slightly accelerated and hold it at about 230ish.
Is this an indication that my torque converter is weak and might be failing? All the while I was doing this no codes were set.
 
ak diesel driver said:
Just checked mine the other day and when the TCC was locked there no slippage
Click to expand...
Is it normal to see the TCC pwm % reading go from 75 or so to settle at 6.5 when it engages and stays locked in? When it showed that after it settled the slippage stayed close to 2 unless I accelerate then the slippage climbs some. I’ll have to do it again to get exact numbers since I was just glancing at the screen and trying to drive
 
ak diesel driver said:
Mine went to 100% and then no slippage
Click to expand...
Maybe I’m looking at the wrong data. Although it’s not connected to the truck in the photo but here’s the values I was looking at. The percentage would spike up then settle down to somewhere near 6.5 while cruising and the slippage would go down to about 2 When I accelerated the percentage wouldn’t move but the slippage would climb. I think I got it up to 250 if I accelerated any more it would climb up quickly and the percentage would go to 0 and released the lockup

I’ll have to put the rear end up on jack stands so I can watch it closer
 

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Now I’m crying. On the way home from work today gave her a little more on the accelerator. The downshift was smooth and picked up speed pretty good but I felt a funny shift as I got up to 60 as was no longer under much of a load accelerating. Other than that all seemed fine. Got home and rechecked codes and there’s two that showed up. The retched 68 for the APP # 3 circuit and a new one. Code 85 undefined ratio error.
This truck can’t have all the sensors failing this quick in a row. I fear I’m loosing my tranny ☹

Any recommendations on what the cost is on a reman and where to on not to go in my area? I had found a used one from LKQ for $600 that has a 6 month or 6k mile warranty. Not sure what a rebuild or another rebuilt tranny would cost
 
JMJNet said:
Sounds like you may have APP issue?
Click to expand...
I had replaced the APP a while back but the code keeps coming up. Not sure what’s causing that. One day going to work I lost throttle function for a moment that when I replaced it. Hasn’t happened again since but the code keeps setting
 
Just re-cleaned all the grounds. Two wires top right of the intake, and one on the inner fender by the right side battery. Will have to search online for troubleshooting steps for the APP and go from there. Weed out all other codes before ruling on the transmission
 
I believe you should have 3 grounds at the back passenger side. 1 is for the PCM 1 is for the transmission and the last one I can't remember at the moment
 
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