Lockup not engaging

turbo96max

Member
Joined
Jun 6, 2007
went back to lockup using a vig 5 disc, new pump w tube mods, new lock up valve. Shop who did the rebuild originally did the work. They reported that lockup was not working and I should verify the ECM.

Thanks to Eric I was able to confirm the ECM logs on the pl show tcc lock being checked at 50mph. But still no actual lock.

The shop said to take it back but I'd like some input on what the ECM is doing .
1. Is it sending a 12 volt signal?
2. Is it interrupting a 12 volt signal to ground?
3. Does anyone know the pin out and expected values for the tcc harness at the Trans and on the ECM?

Maybe they are using the wrong harness ???
 
It's grounding the circuit. Pin out posted on one of the old sites


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KOEO check for power on the pink and black wire at the 4 pin connector on the trans.
Ah currently trying to track down the harness off a gn , the shop used a non gn specific connector w brown and black wires. but from what they said 2 of the wires have power. do you know how many wires should be on the harness? the one he showed me has only 3 wires. and is the power on the pink and black wire supposed to ground out during lockup?
 
did they put the o-ring back on the input shaft
 
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pg 11 ...MAKE SURE ORING IS INSTALLED ON INPUT SHAFT!!

the check valve can be removedor left off from inside the end of the input shaft (optional) but the oring they seem to be very clear on it being in place
 

Attachments

  • install_manual vig converters.pdf
    8.9 MB · Views: 273
As Bison said the ECM makes the ground for the TCC solinoid. You can make the ground manually by grounding pin "F" of the ALDL. Key on enging off, if you ground pin "F" you can/should be able to hear the TCC solinoud clicking on the tranny. If you don't hear it check to make sure the TCC break switch is pushed against the pedal closing the switch. If you hear the click it is most likely not an electrical problem. I thought for a NL converter a check ball capsule is removed from the input shaft??? Beyond that the TCC lock uo apply valve in the front pump may be stuck. I guess the electrical needs to be confirmed first then find out if every thing is back in place for a lock up converter.
 
Guys, so I found no power on pin F after checking , found that the tcc brake switch was not pushed in all the way. so i corrected it. went for a spin to test and manually ground pin f (jumping a & f) . I didnt make it 10 blocks when the ecm fried. coincidence or not?? i dont believe so much in that . but anything is possible. ecm and cci fuse wer still good. but the check engine light didnt blink at ignition any more. so after pushing the car 10 blocks to make it back home i pushed the tcc barke switch back out and plugged in my spare ecm to test. ecm light blinked and the car started right up. I called the shop and the guys said he had done something inside the trans wiring for the 3rd and 4th gear solenoid/pressure switch connections in order to test for lockup. im not sure what he did . i did drive the car 45 mins home like this but the barke switch was not in all the way so pin f was not powered on. thoughts??? is it possible to fry the ecm if you mess up a connection down there on the solenoid? they are using a new aftermarket solenoid which doesnt take the same male harness so it was done manually w blade connectors. any idea what wire i should be looking at ?? the shop said to unplug the trans harness once i get my modded ecm back from Bob and take the car back but at this point i need to know what could have caused the ecm to die so i can make sure they dont fudge another ecm up.
 
Based on your description so far, I doubt I would have much faith in what that shop is doing in your tranny!!
Get the right harness to plug into the tranny, make sure it's all wired up according to the drawing pacecarta supplied above.
And I would pull the pan and make sure the 3rd and 4th gear switches are properly connected (without them you won't get lockup either)

For lockup you need three things, 1. 12v via the brake switch. 2. ground supplied from ecm when conditions are met (lockup speed in chip). 3. 3rd and/or 4th gear switch supplying ground signal back to ecm.
 
Based on your description so far, I doubt I would have much faith in what that shop is doing in your tranny!!
Get the right harness to plug into the tranny, make sure it's all wired up according to the drawing pacecarta supplied above.
And I would pull the pan and make sure the 3rd and 4th gear switches are properly connected (without them you won't get lockup either)

For lockup you need three things, 1. 12v via the brake switch. 2. ground supplied from ecm when conditions are met (lockup speed in chip). 3. 3rd and/or 4th gear switch supplying ground signal back to ecm.


Still dealing with this issue. just got the car back from the shop again, so they hotwired the lock up solenoid it lockup engages. Can you elaborate on point #3?

Right now I dont have 12v in afdl F.

should pin A and D down at the trans have 12v then one of the 2 gets grounded out by ecm? or does A have 12 v and D gets grounded by ecm ? does the ecm need to see the 3rd 4th gear switches ground properly for the ecm to be able to ground pn A?


do the 3rd and 4th gear switches apply ground depending on pressures or always ground out?
 
3 and 4 gear switches are normally closed , they are labeled as NC in the diagram so its should be obvious how they function) and when in 3rd and 4th they open the ecm will flag as such (scan tool will verify)

grounding pin F ..(jump pin F and A) should engage lockup as long as you are in2nd 3rd or 4th gear ,it wont lock in first
 
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manually jumping the aldl pin a n f engages the lockup. tested the ground signal at ecm brown wire and down at the trans, the all change when jumping the pinf a n f. is this pointing to a faulty ecm? powerlogger shows the "lock-up" checkbox get checked at 50 mph. ):
 
The first thing you need to try is pull the pan on the thing and check to see if tranny shop even checked to see if sol. will even fire. pull sol. out or you can even use jumper wire from batt. pos post down to sol. I use a bed of nails but you can use anything you have to probe wire,just make sure u have 12 volts to power side of sol.next use a ground wire to the side that's going to switches theyre are only two wires going to sol. so this wont be hard to figure out turn key on and ground circuit if you here a click sol. is functioning. a lot of times on these older trannys they don't even check to see if pressure switches are working. these are normally open switches when trans shifts into third gear the fluid pressure goes into switch which has a rubber blatter in it and closes the switch, therefore grounding it and energizing the sol. and wallah we have lockup.Now to test these normally open switches, you can use a voltmeter put it to ohms position, I prefer the beep test and apply air pressure to open side of switch and see if meter beeps if it does then switch is good. If all of this is good its something mechanical and you need to take back to trans shop and tell them its mechanical. ie lockup valve o ring missing or something.by the way put meter positive lead on switch and neg. lead to ground,apply air pressure. no beep bad switch.
 
The 3rd and 4th gear switches are normally CLOSED not normally opening. The diagram above clearly shows that. Also the 3rd and 4th gear switches do not make the ground for the TCC solinoid. They are input signals to the ECM. Under the right conditions the ECM sends the ground signal to the TCC solinoid. You don't need to drop the pan to test the solinoid. Turn the key on engine off and ground pin F of the ALDL. If the solinoid is working you can hear the solinoid clicking.
 
I wasn't trying to get in too a big hairy discussion with you I was just trying to help out the fellow asking the question about his non lockup problem. but since you started this discussion, I happen to have a BRF trans torn down in my shop right now as we speek and it has only one n.c. switch on valve body now do you think that youre wiring schematic will work for diagnosing his non lock up problem. although that's not what its in for its in because it smoked the forward and direct cluthes wnd were trying to figure out why, probably a misplaced check balls or pressure problem we don't know yet we didn't build unit. my point to all this is these cars are almost 30 years old and have been tinkered with a bunch by who knows how many people now if it were 1987 then I wwould probably say youre schematic might be fine to use but the gentleman already said it had a different harness in it so who knows what else was tinkered with. im trying to help him figure out why he doesn't have lockup now with common sense electrical advice not if its not hooked up exactly like the sschematic shows it wont work. I personally don't like my performance cars to even lockup in 3rd gear only in 4th when cruising but I guess sine the schematic says lockup wont work unless its wired this way I guess Im out of luck.
 
i appreciate the help guys.. so just to summarize:
1. i get lockup when manually grounding the ecm a7 via aldl
2.confirmed continuity on that a7 wire down to the trans

heres what got me thinking now about the switches and im not sure how they fit into the mix

powerlogger 3rd and 4th gear flags never show up 'checked' but at 55 mph the lock-up flag is 'checked' (but ecm is not grounding pin a7)

Shop said they located a factory solenoid harness for inside the trans and put new aftermarket solenoids (reportedly) .

does the ecm need to receive that signal from the solenoids in order for the ecm to ground a7?
are they sending 12v signal when in 3rd and 4th or are they not sending signal when in 3rd and 4th?

im uploading a file so anyone that wants to can see the checkboxes im talking about
 

Attachments

  • lockuptestno34check.dat
    123.5 KB · Views: 36
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Ok turbo96max here we go, lets start from scratch.Bison was right about the ecm controlling the l/u sol. on the ground side. and according to that schematic there are two pressure switches on a brf valve body or whatever that schematic is for, not even sure that's for a brf tranny.now the problem that I have is I think the schematic is wrong or not for this car,i have been in this industry for a long time and believe you me Ive seen plenty of things wrong on schematics. I happen to have a brf torn down in my shop as we speek and guess what, only one pressure switch and its normally OPEN. I looked at my schematics and I have all of them for everyone of the other 200s for the other cars but cant seem to find one for this particular tranny and it shows them to be n.o also but either way, that is all a moot point anyway and heres why. you don't need to know if they are a n.o switch or n.c switch, just whether or not its sending a signal to the ecm saying hey im in third gear ,or forth gear ,however yours is set up, so it can energize the l/up sol., and quit exhausting fluid into the pan and allow the lock up valve in pump to be stroked, and apply the clutch. Now that weve cut through some of the garbage, lets start diagnosing. If this car came in to my shop this is how and where I would start. turboburick was right first place to start is to make sure we have 12 volts down to trans on red wire cavity a,thats 12 volts with a meter not I have juice with a test light.Now if we don't have 12 volts down to trans we need to do a voltage drop test, in other words we need to start looking to see where we lost our voltage and start backtracking that circuit backwards towards the voltage source until we find it. First place I would look is the easiest place to acces, fuse or brake switch,once we find where we lost it fix the problem and youre back on the road again.Now if we have voltage down to trans. then obviously that isn't it and we need to go further in our diag. Ok so our next step will be control side, which in this case is the ground side of the circuit the ecm. Now this is how I would personally go about this, the f pin on the aldl connector is on the ground side of the l/up sol. so lets look at this scenario, say you ground this sol. through the aldl connector and wallah it clicks 15 times, you say well it must the computer not supplying a ground, but how do you climb into the computer and see if its doing its job or not, grounding the circuit. This is where a lot of technicians start throwing parts at it. Me, I want to know if its in the computer before I stick my neck out on the line and tell the customer you need a computer for x amount of dollars, and cross my fingers that it fixes it, knowing full well Im not 100% sure.So on to more diagnostics, hang with me almost there. Remember the reason I personally don't like checking the ground side of the circuit from the aldl it leaves out the rest of the wiring in the ground circuit, the connector to the ecm, and the ecm.So now what,we need to see if the wiring is good between the trans connector and computer, black wire ,terminal d. Ok now, there are several ways to do this and how most people are taught is the ohms test which I don't care for and ill tell you why, automotive wiring is made in strands and not solid like house wiring, if I cut 6 of the seven strands of wire and ohm it , guess what, it will test good , but it will not I repeat will not carry a load. Now to test it get a wire from youre local parts store with a fuse holder, and use a fuse, now jumper that wire to ground unplug the connector from ecm,and find socket from the trans ground wire. now on this end youll need a headlight bulb from a new car and jumper it over to battery pos. if it lights up nice and bright you've just determined that that circuit is good and can carry a load. now disconnect yourelight bulb and youre jumper and plug in the connector down at trans. and leave ecm connector unplugged, turn key on engine off, ground ecm wire to battery see if sol. clicks if it does its either computer driver in ecm ,or its the pressure switch not sending signal to ecm. to ground l/up sol.If this doesn't lead you to the fix let me know and ill tell you how to trouble shoot pressure switch, its the last thing left. I apologize to every one out there for such a long post I just know that this plagues a lot of people,so my apologies.Bye the way sometimes the sol. check ball after it gets energized once will stick and you wont here it click again you have to pull the sol. out and apply a little air pressure to the snout down bye the o ring.
 
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