torque conveter lockup help
10-15-2013, 07:45 PM
#1
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torque conveter lockup help I just bought a yank ss3200 converter and after putting it in the car goes in and out of lockup. you will be cruising at 55-60 and it wont go in lockup or does and will come out it will eventually go in but will come out again. my scan tool say the converter is getting a command to be out of lockup when it is not in. my question is what is giving it this false command. the only dtc code is P0507 witch is idle air control. will the mess with my lockup? if so any advice on how to fix the 507 code will be helpful because I cant figure it out. thank you
10-15-2013, 08:51 PM
#4
It helps if you tell us what year the car is as this section covers three different computer systems.
The pcm sends the lockup command so reprogramming it is usually recommended after adding a stall.
Also is the engine stock?
Are the gears stock?
The stock converter is so tight you might not have noticed it cycling in and out.
The pcm sends the lockup command so reprogramming it is usually recommended after adding a stall.
Also is the engine stock?
Are the gears stock?
The stock converter is so tight you might not have noticed it cycling in and out.
10-15-2013, 09:08 PM
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The car is a 1996 z28 all stock besides midlength headers 3:42 gear I reprogrammed using a hypertech tuner. Also at the track I spray a 125 shot. It wasn't doing it with the stock converter. I also had a acc converter in before the yank that I changed because it was unbalanced but the lockup worked on that one. All I did was change to the yank converter and added a trans cooler.
10-18-2013, 02:55 PM
#6
That Hypertech can do more harm than good.....particularly with a car that's been modded.
I'd say that the lack of a tune (for that 3200 stall TC) is the issue.
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10-24-2013, 04:50 PM
#8
Hypertech is not the problem, especially since it was OK after the Hypertech and not OK after the converter. I would check the grounds first. The TCC solenoid inside the Trans could have failed. Coincidences do happen. More likely a ground disturbed during the install.
Not sure what would lead a person to think tuning changes are needed to keep a higher stall speed converter locked up. No tuning changes needed.
Not sure what would lead a person to think tuning changes are needed to keep a higher stall speed converter locked up. No tuning changes needed.
10-24-2013, 05:40 PM
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it might be a ground. the computer is telling the converter to not go in to lockup when it falls out I just do know what will tell the computer to take it out of lockup when it should be in. will a ground do this and does my p0507 code I cant fix have anything to do with the converter. thanks.
10-24-2013, 11:01 PM
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It is not that easy to find out what is doing it. I have a good scanner and my dad is a gm master tech I have been looking at it with the scan tool for a month and can't figure it out its not the brake switch the scanner shows it stays open when the converter comes out of lockup. Any other ideas? Thanks
10-25-2013, 07:40 AM
#13
A master tech should be able to watch the brake switch parameter on his Tech2, to verify it changing as you press and release the brake pedal. It will show the TCC commanded "off" when the brake pedal is pressed, also if it sees too many misfires per second. A poor ground would still show the TCC commanded "on" when it unlocked, when it shouldn't unlock.
10-25-2013, 08:58 AM
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The brake switch is working according to my tech 2. I press the brake and it goes from open to closed in the tech two. When I drive and it comes out of lockup the tech 2 say the tcc is enable and that means something is give the computer a command to not go into lockup. Misfires are ok any other ideas because everything is normal besides iac counts. Thanks
10-25-2013, 09:15 AM
#15
If it commands the TCC to unlock when it does this, your dad should be able to diagnose it. Look at the misfire monitor. If it still shows it commanded "On", check for voltage on the TCC wire from the Trans to the PCM. Voltage there indicates poor ground. If that is the case, back probe the PCM grounds at the PCM, voltage on a wire there when it unlocks indicates the poor ground wire.
Of course, a master tech already knows all this.
Of course, a master tech already knows all this.
10-26-2013, 08:04 PM
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I went out tonight to try and fix my lockup problem. when the car went out of lockup the tcc enable was no. when it was on and working fine it said yes. when the car went out of lockup my tcc duty cycle was going from 10% to 90% and kept going back and forward between these to numbers until it went into lockup. a few mins later I got two engine codes p0507 and p0400. anymore ideas what it could be thanks.
10-26-2013, 09:14 PM
#18
Your minimum air rate needs adjusted. The throttle blade is evidently open too far, or you have a vacuum leak. P0507
You also have an EGR issue. P0400
Your PCM is seeing an issue causing it to unlock the converter. It likely isn't a ground if the PCM is commanding it off.
An auto tech that is sharp at diagnostics could find this for you. There are any things that could cause this. 90% of the possibilities would show up on a Tech2 scan tool if you knew what too look at. Could be excessive misfires, indicated temp issues, possibly the EGR could could cause it. A GM shop manual would tell you in the TCC trouble shooting section. The TPS could have a dead or dirty spot on the resistor. Scan tools will very seldom show that up. The data stream is just way too slow with data updates. Takes a fast DSO to find that normally.
If your Dad is a GM Master Tech he should be able to find this for you.
Is this engine stock?
You also have an EGR issue. P0400
Your PCM is seeing an issue causing it to unlock the converter. It likely isn't a ground if the PCM is commanding it off.
An auto tech that is sharp at diagnostics could find this for you. There are any things that could cause this. 90% of the possibilities would show up on a Tech2 scan tool if you knew what too look at. Could be excessive misfires, indicated temp issues, possibly the EGR could could cause it. A GM shop manual would tell you in the TCC trouble shooting section. The TPS could have a dead or dirty spot on the resistor. Scan tools will very seldom show that up. The data stream is just way too slow with data updates. Takes a fast DSO to find that normally.
If your Dad is a GM Master Tech he should be able to find this for you.
Is this engine stock?
10-26-2013, 09:52 PM
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Ya I know what the codes are and you would think this issue would be easy to find but it isn't. The car has a yank 3200 ss converter 3.42 gear and a 125 shot of nitrous. The tps, tcc brake switch and map sensor all work. I know something is telling the converter to come out of lockup but I can't find it all the telemetry looks good. Anyone's ideas thanks