Can you guys help me with unlocking converter problem&code?
04-06-2013 | 11:08 AM
#1
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From: Michigan
Can you guys help me with unlocking converter problem&code? Just had my tranny rebuilt with the 4k stall ...cam installed/dyno tuned.
When cruising at 55mph or anthing after lockup, my converter randomly unlocks then locks back up throughout driving,mostly after its warmed up. Kinda feels like a downshift.So if I'm cruising at 55mph at 1900rpm....it suddenly jumps to 2300rpm (unlocks I think).Then it will randomly lock back up.
It also recently threw the p0751 "shift solenoid "A" performance or off " Any help is much appreciated . I have a small window of time to correct these issue
When cruising at 55mph or anthing after lockup, my converter randomly unlocks then locks back up throughout driving,mostly after its warmed up. Kinda feels like a downshift.So if I'm cruising at 55mph at 1900rpm....it suddenly jumps to 2300rpm (unlocks I think).Then it will randomly lock back up.
It also recently threw the p0751 "shift solenoid "A" performance or off " Any help is much appreciated . I have a small window of time to correct these issue
Last edited by justin hover; 04-06-2013 at 12:07 PM.
04-08-2013 | 06:39 PM
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Misfires were deleted during dyno tune. I'm left with a bunch of options but don't know where to start. Brake pedal...solenoid...other things I'm not familiar with. I just don't want to end up at the shop 2-3 more times paying more money seeing what works and what doesnt. I wasn't expecting this issue...thought a locking/unlocking converter was fool proof.
Now I'm stuck with a randomly locking..but mostly unlocked converter that is just killing my gas. I'm trying to come up with as many options as possible to do in one day at the shop...just not too sure which ones yet.
Now I'm stuck with a randomly locking..but mostly unlocked converter that is just killing my gas. I'm trying to come up with as many options as possible to do in one day at the shop...just not too sure which ones yet.
04-08-2013 | 07:23 PM
#5
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From: Ann Arbor, MI
Check how sensitive your brake pedal switch is to motion. With engine off, ignition on, have someone watch your brake lights while you push the brake pedal with your hand. If the brake lights turn on with only e.g. 1/8" of movement, that might be too sensitive. I would aim for at least 1/2"; there might be adjustment on the switch or a bracket to bend.
Yes, its a wild shot, but I am not making this up - this was the solution on at least two threads in the past year, describing the same problem.
Yes, its a wild shot, but I am not making this up - this was the solution on at least two threads in the past year, describing the same problem.
04-08-2013 | 11:11 PM
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From: Wichita KS / Rancho San Diego
There are a number of DTC's that have to be turned off with a higher stall converter. Otherwise they will give trouble like what you're experiencing, or cause the tranny to go into limp mode. Do you have the ability to continue to tune your car?
04-09-2013 | 06:07 AM
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No...I can only data log through my torque app. Can't remember everthing though I will call to refresh my memory but....torque managment is gone....line pressure is up (I need/am getting a shift kit) misfires deleted, tcc or tpp or something like that,, values were maxed out. What other tuning terminology should know about? Or bring up? I can always send my pcm back to my tuner to avoid the drive. When it was dyno tuned just a couple weeks ago everthing was fine. Then a couple drives later this started.
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04-09-2013 | 11:15 PM
#8
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From: Wichita KS / Rancho San Diego
When I installed my TCI SF3000 stall, the only tuning I did was for driveability and performance. When I moved up to a Yank SS3600, I had problems with tranny going into limp mode and other issues and they were solved only by disabling reporting for certain codes. The PCM never threw an SES light.
Read the section on codes from this thread in the stickies https://ls1tech.com/forums/automatic...lush-more.html Some P075x codes and P1870 might need to be tuned to not report. I had to raise the threshold for misfire reporting in the low and mid rpm range for certain cells. I also had problems with a false P0502.
Read the section on codes from this thread in the stickies https://ls1tech.com/forums/automatic...lush-more.html Some P075x codes and P1870 might need to be tuned to not report. I had to raise the threshold for misfire reporting in the low and mid rpm range for certain cells. I also had problems with a false P0502.
Last edited by RevGTO; 04-09-2013 at 11:49 PM.
04-10-2013 | 10:48 PM
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From: Wichita KS / Rancho San Diego
04-12-2013 | 07:44 PM
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From: Michigan
I thought 4l60s didn't have limp mode? I'm almost positive I've read that before.
04-12-2013 | 08:13 PM
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From: Ann Arbor, MI
04-12-2013 | 08:33 PM
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Thanks for clearing that up, Im thinking about replacing the solenoid for the PO751 code and going from their. Though I thought that was just for 1-2 shift stuck off, and my car shifts just fine. I did clear that code and it never came back on....just the damm converter unlocking/ locking 5 times in 10 miles..sometimes it didn't lock but once. I tried the brake switch with no difference. If its not that solenoid I'm gonna be pissed..were digging pools ***** to the wall and don't have anytime.
04-16-2013 | 04:12 PM
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From: So.Cal.
Can you log the brake pedal switch and misfire counter when TCC unlocks...?
Also there are pids that indicate the reason for unlocking the TCC.
Also there are pids that indicate the reason for unlocking the TCC.
Last edited by joecar; 04-16-2013 at 04:18 PM.
04-16-2013 | 05:38 PM
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From: Ann Arbor, MI
Justin: Having read many of your posts and noticing your interest in knowing all the details, you should spring for a full tuning package like HP Tuners.
As Joecar points out, you can then log various parameters and debug this problem.
However, I think you would really enjoy the engine engine tuning process, which really is a must as you make mods.
As Joecar points out, you can then log various parameters and debug this problem.
However, I think you would really enjoy the engine engine tuning process, which really is a must as you make mods.
04-16-2013 | 06:37 PM
#16
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From: So.Cal.
In EFILive you would look at the following pids to diagnose TCC unlock:
Code:
Status parameter {GM.TSTATE03}
Transmission State 03
(Bitmapped PID)
Description Status=0 Status=1
Unused - -
Cruise Control Status Off On
Unused - -
Throttle Kickdown Mode Active No Yes
TCC Release Switch Status (4T40 only) Off Released
Fuel Power Enrichment Mode Active No Yes
A/C Clutch Status Off On
Cruise/TCC Brake Switch Released Depressed Code:
Status parameter {GM.TSTATE09}
Transmission State 09
(Bitmapped PID)
Description Status=0 Status=1
TCC Off Due To Slip No Yes
Unused - -
TCC Off Due To Downshift No Yes
TCC Off Due To Throttle Change No Yes
TCC Off Due To Brake On No Yes
TCC Off Due To Cold Engine No Yes
TCC Off Due To Cold Transmission No Yes
TCC Off Due To Range No Yes Code:
Status parameter {GM.TSTATE10}
Transmission State 10
(Bitmapped PID)
Description Status=0 Status=1
TCC Fully Locked No Yes
TCC Off Due To Misfire No Yes
Unused - -
Unused - -
Unused - -
Unused - -
TCC Off Due To Minimum Throttle No Yes
TCC Off Due To Upshift No Yes Code:
Status parameter {GM.TSTATE12}
Transmission State 12
(Bitmapped PID)
Description Status=0 Status=1
Unused - -
Unused - -
Unused - -
TCC At Maximum Pressure No Yes
3-2 Solenoid PWM >0% No Yes
Shift Solenoid B state Off On
Shift Solenoid A state Off On
TCC State Off On Code:
Status parameter {GM.TCCMODE}
TCC Mode
(Enumerated PID)
Value Caption Description
0 Off TCC Off
1 Rel TCC Releasing
2 App TCC Applying
3 AppEn TCC Apply Enabled
4 Lock TCC Locked
5 Coast TCC Coast
6 Slew TCC Slewed
04-16-2013 | 07:22 PM
#17
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From: Ann Arbor, MI
Nice doco Joecar. I didn't know there were bitmapped PIDs. I have not seen them documented in HP Tuners, but I suspect they can be accessed.
Justin: That should give you some idea of how much additional information is available when scanning with EFILive (and perhaps also with HP Tuners).
----------------------
There are 10 kinds of people in this world - those who understand binary (bitmapped) numbers and those who don't.
Justin: That should give you some idea of how much additional information is available when scanning with EFILive (and perhaps also with HP Tuners).
----------------------
There are 10 kinds of people in this world - those who understand binary (bitmapped) numbers and those who don't.
Last edited by mrvedit; 04-16-2013 at 10:39 PM.
