Transmission stuck in lock up. Electric problem.

[WoT87]

Ok... My car started acting weird.. Seemed sluggish. Upon further inspection I noticed that the converter was staying in "lock" mode.. Ok so I changed the whole transmission and converter, was going to do it at some point anyway. So everything is changed out and the problem is still there... Ok now I'm in panic mode and really have no clue what's going on. I figured let me pull the plug on the transmission and that will tell me if it's an electrical problem. Well I didn't do that. I just pulled the 7th pin on the ECM tan/black line.. Great problem solved right? Car is running great and it is but now I have no lock up.. So... I buy a new ECM put the pin back in and bam!! Still good problem solved so I thought. After checking a few times by right foot gas on highway and left foot tapping brake pedal, everything seem good.. So this is my problem that I need help with. It's happening again. I can't figure it out. It's definitely not mechanical. So what can it be?? Brake switch or Broken wire somewhere? Please anybody ever have this problem? I have a tun of upgrades just waiting to go on the car but I won't install anything till I kill this demon!! So to recap. Old ECM stuck in lock up. New ECM worked for a few miles and failed as well. I'm stuck with a wire hanging out of my ECM but the car is driving great. If I plug in the wire... Oh boy. I'm getting knock, shaking and just very poor performance. This post not only will help me but the new comers as well. Come on people I know someone had to go through this one time or another.

 

[dank GN]

I would just put that wire on a switch so when at the strip u can force it to lock up . I know it will suck cruisin around to have to flip a switch but it's better then my Reverse Manual Valve Body where I have to shift it .

 

[WoT87]

I'm just trying to make a stock cruiser. Just your basic upgrades. TT chip 60lb injectors. It's this lock up problem that's messing with me. It's so weird how it was fixed after a new ECM than bam!! Back to the same old problem. I'm stuck.

 

[fastblackracing]

First there are several things that are supposed to happen for lock up to occur.

1. As the 1-2 shift valve in the VB moves it sends oil to the 2nd gear servo to push the pin that applies the second gear band. It also sends that same oil to the lock-up solenoid. The system is ready for lock up now but should only do so if the solenoid wire is grounded either through the ecm [tan/black wire] or a manual switch. The ecm normally only applies the circuit in 3rd and 4th gears. I never had it apply in 2nd unless I manually toggled it. But it is possible.
2. There is no oil being sent to the lock up solenoid circuit if the trans is in first gear, if the converter is locking in first, or at the stop sign when the car is stopped it is not likely that the ecm is commanding it and even if it was there is not supposed to be any oil being sent to the lock up solenoid anyway since it comes from the 1-2 shift valve.
3. You can hook an ohm meter to ground and the tan/black [re attached to the ecm] wire and drive the car and you will see on the meter when it grounds and when it is open.
4. So this leaves the most likely culprit is the lock up valve itself which is located on top of the lock up solenoid......what is likely happening is once the valve is in the unlocked position, all is good but after a few lock/unlock applications the valve is binding in the bore and staying in the lockup position until it un-sticks itself whether from dirt or metal debris, varnish build up on the valve/bore, heat/warped bore etc....if this is the case you will need to pull the valve assembly and clean/polish everything until it is butter smooth and all friction is gone, now if the trans is failing and sending crap into the system thats another issue.
5. less likely but possible the converter is failing mechanically and needs replaced.
6. So verify the lock/unlock command signal on the tan/black wire is happening when it should be and then move on to the lockup valve itself.
7. The lockup valve gets oil from the converter feed circuit....the lockup solenoid gets oil from the 1-2 shift valve....when the solenoid is turned on by ecm or manual switch it causes the lockup valve to move which then locks the converter.....
8. This is how the converter can stay locked even when the solenoid is not turned on....since the lockup valve has a constant oil supply from the converter feed circuit if the valve sticks it will make the converter lock when it should not.

 

[MAK507]

First there are several things that are supposed to happen for lock up to occur.

1. As the 1-2 shift valve in the VB moves it sends oil to the 2nd gear servo to push the pin that applies the second gear band. It also sends that same oil to the lock-up solenoid. The system is ready for lock up now but should only do so if the solenoid wire is grounded either through the ecm [tan/black wire] or a manual switch. The ecm normally only applies the circuit in 3rd and 4th gears. I never had it apply in 2nd unless I manually toggled it. But it is possible.
2. There is no oil being sent to the lock up solenoid circuit if the trans is in first gear, if the converter is locking in first, or at the stop sign when the car is stopped it is not likely that the ecm is commanding it and even if it was there is not supposed to be any oil being sent to the lock up solenoid anyway since it comes from the 1-2 shift valve.
3. You can hook an ohm meter to ground and the tan/black [re attached to the ecm] wire and drive the car and you will see on the meter when it grounds and when it is open.
4. So this leaves the most likely culprit is the lock up valve itself which is located on top of the lock up solenoid......what is likely happening is once the valve is in the unlocked position, all is good but after a few lock/unlock applications the valve is binding in the bore and staying in the lockup position until it un-sticks itself whether from dirt or metal debris, varnish build up on the valve/bore, heat/warped bore etc....if this is the case you will need to pull the valve assembly and clean/polish everything until it is butter smooth and all friction is gone, now if the trans is failing and sending crap into the system thats another issue.
5. less likely but possible the converter is failing mechanically and needs replaced.
6. So verify the lock/unlock command signal on the tan/black wire is happening when it should be and then move on to the lockup valve itself.
7. The lockup valve gets oil from the converter feed circuit....the lockup solenoid gets oil from the 1-2 shift valve....when the solenoid is turned on by ecm or manual switch it causes the lockup valve to move which then locks the converter.....
8. This is how the converter can stay locked even when the solenoid is not turned on....since the lockup valve has a constant oil supply from the converter feed circuit if the valve sticks it will make the converter lock when it should not.

Can this problem be witnessed on a PowerLogger recording?
I don't know what any of this means (locked/not locked) etc. but I've been experiencing similar issues as Op has mentioned.


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[WoT87]

Anybody??

 

[fastblackracing]

Anybody??

The answer is in my post but it will require some work on your end.
There are only a few things that can cause your issue.

 

[WoT87]

First there are several things that are supposed to happen for lock up to occur.

1. As the 1-2 shift valve in the VB moves it sends oil to the 2nd gear servo to push the pin that applies the second gear band. It also sends that same oil to the lock-up solenoid. The system is ready for lock up now but should only do so if the solenoid wire is grounded either through the ecm [tan/black wire] or a manual switch. The ecm normally only applies the circuit in 3rd and 4th gears. I never had it apply in 2nd unless I manually toggled it. But it is possible.
2. There is no oil being sent to the lock up solenoid circuit if the trans is in first gear, if the converter is locking in first, or at the stop sign when the car is stopped it is not likely that the ecm is commanding it and even if it was there is not supposed to be any oil being sent to the lock up solenoid anyway since it comes from the 1-2 shift valve.
3. You can hook an ohm meter to ground and the tan/black [re attached to the ecm] wire and drive the car and you will see on the meter when it grounds and when it is open.
4. So this leaves the most likely culprit is the lock up valve itself which is located on top of the lock up solenoid......what is likely happening is once the valve is in the unlocked position, all is good but after a few lock/unlock applications the valve is binding in the bore and staying in the lockup position until it un-sticks itself whether from dirt or metal debris, varnish build up on the valve/bore, heat/warped bore etc....if this is the case you will need to pull the valve assembly and clean/polish everything until it is butter smooth and all friction is gone, now if the trans is failing and sending crap into the system thats another issue.
5. less likely but possible the converter is failing mechanically and needs replaced.
6. So verify the lock/unlock command signal on the tan/black wire is happening when it should be and then move on to the lockup valve itself.
7. The lockup valve gets oil from the converter feed circuit....the lockup solenoid gets oil from the 1-2 shift valve....when the solenoid is turned on by ecm or manual switch it causes the lockup valve to move which then locks the converter.....
8. This is how the converter can stay locked even when the solenoid is not turned on....since the lockup valve has a constant oil supply from the converter feed circuit if the valve sticks it will make the converter lock when it should not.

Thank you very much for the reply.

So this was happening with the original transmission as well that's why I changed it out. I thought it was a mechanical issue. As soon as I got in it with all the new parts the problem was still there. Maybe your right, I'll need to check for ground problem?? I know for a fact the trans and converter are in mint condition. The car is a beast with that wire pulled. If I put it back... Complete dog!! Knock @13.5 just crazy stuff happens. It don't stall out when I come to a stop though. Just seems rough on the stop and highway driving. Like if I want it to downshift, that's not going to happen without a lot of knock/retard going on. I'm just lost at this point. It was fine all day with that new ECM. I would bet the bank if I bought a new ECM again it would be ok and take a dump again. This sux!!

 

[WoT87]

The answer is in my post but it will require some work on your end.
There are only a few things that can cause your issue.

Yeah fun fun. Thank you very much for passing the knowledge alone to me and others who might read this. Much appreciated.

 

[RmvBfrFlght]

Most likely there is a shorted solenoid or relay that the ECM is also driving. That takes out the quad-driver in the ECM, which then affects the TCC lockup. Off hand I don't know which devices share the same driver that the TCC is on. But here are some items that are driven by the ECM:

Low speed fan relay, A/C cutoff relay, EGR solenoid, CCP solenoid, wastegate solenoid, SES light, ALDL data(?).

Check the resistance of each device, it needs to be above 22 ohms or so.

RemoveBeforeFlight

 

[wb_7354]

Subscribed. I exited the expressway. While slowing to a stop I noticed the car hadn't downshifted and was about to stall. I shifted into neutral before the car stalled. I shifted into drive and the trans flared on both shifts. At the next stop. I shifted into neutral before stopping. I then switched off the A/C and everything was completely normal. Not meaning to hijack your thread. Seems like maybe a piece of the puzzle??


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[WoT87]

Most likely there is a shorted solenoid or relay that the ECM is also driving. That takes out the quad-driver in the ECM, which then affects the TCC lockup. Off hand I don't know which devices share the same driver that the TCC is on. But here are some items that are driven by the ECM:

Low speed fan relay, A/C cutoff relay, EGR solenoid, CCP solenoid, wastegate solenoid, SES light, ALDL data(?).

Check the resistance of each device, it needs to be above 22 ohms or so.

RemoveBeforeFlight

So I check each relay? All fan relays? 20 ohms right? If it's below than its no good?

 

[WoT87]

So I check each relay? All fan relays? 20 ohms right? If it's below than its no good?

Sorry 22 ohms. I get intimidated by electronics. I have no clue how to use an ohm meter. This should be fun.

 

[RmvBfrFlght]

So I check each relay? All fan relays? 20 ohms right? If it's below than its no good?

Just the low speed fan relay, the ECM isn't connected to the other two. To test for example the CCP purge solenoid (left front, under hood), unplug the connector and measure the resistance between the two terminals of the solenoid.

If the DVM doesn't auto-range, use the 100 or 200 ohms range for testing. Do this with all of the devices I listed. IIRC, relay coils are usually higher in resistance, so we want to look for the one that is lower then 22 ohms.

RemoveBeforeFlight

 

[WoT87]

Just the low speed fan relay, the ECM isn't connected to the other two. To test for example the CCP purge solenoid (left front, under hood), unplug the connector and measure the resistance between the two terminals of the solenoid.

If the DVM doesn't auto-range, use the 100 or 200 ohms range for testing. Do this with all of the devices I listed. IIRC, relay coils are usually higher in resistance, so we want to look for the one that is lower then 22 ohms.

RemoveBeforeFlight

Ok this is good information... What a CCP purge solenoid? And what's a DVM? This is probably a simple and stupid question but I really don't know anything about the electronics on these cars and I really want to learn. Also I know with the fan relays, counting starting from the front which relay is it? I know the big one in the back is the high/low but which one out of the two little guys is the one I need to be testing. And do I need a special volt meter to test these or Can I get a meter for Pep Boys or something? So just to recap I'm going to look for a 22 Ohm or lower reading and that's the culprit right?

 

[RmvBfrFlght]

CCP is the charcoal canister purge system. It is the black can with the two hoses on it. Solenoid has a red connector plugged into it.

I'm not sure which relay is the low speed one. It will have a GRN wire going to it while the high speed relay will have a GRN w/YEL stripe wire going to it.

DVM is digital volt meter. Can get one from an auto store, Harbor Freight also has them.

So just to recap I'm going to look for a 22 Ohm or lower reading and that's the culprit right?

Yes, I measured the CCP solenoid not long ago and it was about 24.5 ohms.

RemoveBeforeFlight

 

[wb_7354]

Any updates on this??


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[WoT87]

Any updates on this??


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I have no clue what to do. I might have to bypass the ECM. Put a vac switch. Unless anyone can solve it. I'm done. When it comes to wires I'm no good.

 

[WoT87]

Subscribed. I exited the expressway. While slowing to a stop I noticed the car hadn't downshifted and was about to stall. I shifted into neutral before the car stalled. I shifted into drive and the trans flared on both shifts. At the next stop. I shifted into neutral before stopping. I then switched off the A/C and everything was completely normal. Not meaning to hijack your thread. Seems like maybe a piece of the puzzle??


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I gotta try that. Maybe put my AC on. Who knows. I'll get back to you on this. Thanks.

 

[wb_7354]

My car has been running flawlessly since that incident. I honestly don't know how the AC could effect the trans lockup but it did. I think you should call or pm Dave Husek. He will tell you what's up with your car.


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