Guest imported_dantm4 Posted January 8, 2004 Share Posted January 8, 2004 I think my vibration might be the TCC refusing to disengage, but I'm unsure after reading some other posts how I might be able to toggle it on and off to find out through the diagnostic system. Probably isn't that hard but haven't quite figured out the transmission diagrams from reatta.net, anyone care to explain how to do it as simply as possible? -Dan90' coupe Link to comment Share on other sites More sharing options...
2seater Posted January 9, 2004 Share Posted January 9, 2004 The TCC can be toggled on and off through diagnostics. You must be cruising in third or fourth gear for this to be active, although you can enter diagnostics and get to the proper area before starting to drive, as long as the engine is kept running. Enter diagnostics in the normal way, with the engine idling, by pressing "off" and temperature ^ (up) at the same time. Hold for a couple of seconds and the entire IPC should light up. Release the buttons. The odometer on the IPC will now go through any trouble codes that may be stored. When it is finished with this it should read "Ec?", press "fan up" on the climate control and the readout should change to "data Ec?", press "fan down" on the climate control and the readout should change to "Input Ec?", press "fan down" again and you should see "output Ec?", press "fan down" one more time and you should be at "or ide Ec?", press "fan up" to enter the overide section. At this point the odometer should read "ES00", press "fan up" one more time and you have arrived at "ES01" which is the torque converter overide. There should also be the number "0" below the ES01 on the display. This indicates the torque converter is unlocked. You should now drive the car and after reaching a speed where the converter will be locked, you press "temp. down" to turn the converter off and "temp.up" to turn it back on, and the number on the display should change to "99". You will need to maintain some pressure on the throttle as you are cruising, or the converter may unlock because you are coasting down, as the ECM will see the low voltage from the TPS as closed throttle. There is also an indicator on the climate control panel to indicate if the torque converter is locked. Observe the "medium" fan speed indicator on the climate control. If it is lit, the torque converter is being signaled to lock, if it is not, it is unlocked. The torque converter clutch circuit is always powered when the key is on, and the ECM turns the ground for the solenoid on and off to cause the lockup. If there is a wiring problem, where the lockup wire may be grounded, the converter may not respond to the lock-unlock signal, although if the converter remains locked as you come to a stop the engine should stall out. As a last resort, you can disconnect the transmission wiring harness at the top front of the transaxle housing. It is a round four or five wire connector and this will disable the converter lockup as well as the gear signals to the ECM. The car can be driven this way, although the check engine light may come on as the gear signals will be missing to the ECM, which are used to determine the correct EGR operation, among other things. Oh, one last thing, just press "bi-level" to exit diagnostics or turn the key off. Link to comment Share on other sites More sharing options...
Guest imported_dantm4 Posted January 9, 2004 Share Posted January 9, 2004 Thanks, I'll try it tomorrow on my trip to Dayton, you mentioned keeping the throttle open, could I toggle on/off with the cruise control on or will it disengage as soon as I release the TCC? It will disengage before the car stalls out while stopping but does feel like it's going to stall when coming to a stop. -Dan Link to comment Share on other sites More sharing options...
2seater Posted January 9, 2004 Share Posted January 9, 2004 Good question on the cruise control. I do not know what the reaction would be but it should do no harm to try it. It may cause the cruise to surge as you toggle the lockup as the rpms should change some when the lockup goes away an vice-versa. Link to comment Share on other sites More sharing options...
DougG Posted January 10, 2004 Share Posted January 10, 2004 May I inquire as to the symtoms you are experiencing?When do the vibrations occure?My 89 shutters when in OD around 50-55 mph,when under a slight load.I've replaced:plugs,wires,coil pack,but no change. Thanks DougG Link to comment Share on other sites More sharing options...
Guest imported_dantm4 Posted January 10, 2004 Share Posted January 10, 2004 I think after reading several posts that this seems to be a common problem among Reatta's. The problem just started appearing a few weeks ago. Initially I thought a number of things, tires out of balance (but they're fairly new), perhaps too much transmission fluid in the reservoir (I added some trans-x to it since I was unsure it had been changed) Have since found out it was never changed while my grandfather owned it (75K miles - he bought it used at 15K).I'm experiencing vibration anywhere from about 40 to 70 miles an hour. It could still be several things (bad gas?, cold weather, road conditions), including the tranny fluid somehow, but have also been experiencing what has been referred to as the "unwillingness to disengage" symptom like when you don't push the clutch in on a manual transmission and you try to stop. It vibrates then. It's possible that it might be a coil, but the wires and plugs have been replaced and the car seems fine - until it warms up, which makes me think it's the TCC since it won't engage until the tranny is warmed up (at least that's what I got out of reading the FSM on how the tran. works) I'm going to dayton today from cincinnati - long trip, ample time to warm up, so I'm going to check the TCC with the manual override and see if it helps. If it doesn't, I'll move on to other factors, and probably have the fluid replaced next (which needs to be done anyway, but might solve this problem, or at least help) Hope some of this helps someone else, I'll keep posting till it stops....-Dan Link to comment Share on other sites More sharing options...
2seater Posted January 11, 2004 Share Posted January 11, 2004 Essentially, the car has to reach closed loop operation before the torque converter clutch will operate, there is no transaxle temperature switch that I am aware of. When closed loop is reached, several things happen, in addition to the lockup enable. When cold/open loop, the engine runs on the preprogrammed information in the ECM, which is a fairly rich fuel/air ratio. When closed loop and the O2 sensor is modifying the mixture, is is no doubt a leaner mix. It takes more spark energy to fire a lean mixture than a rich one, so a weak ignition system may only show up when warmed up. Link to comment Share on other sites More sharing options...
Guest imported_dantm4 Posted January 12, 2004 Share Posted January 12, 2004 Didn't consider that to be a possibility but maybe I'm experiencing the beginnings of a bad coilpack. It didn't appear to be the TCC on the trip to Dayton, but didn't really experience the other lock-up symptoms either during braking so maybe it was happy for the trip. The cruise control did still work while trying it - just jumped the RPM's about 300. If the coil went bad, would the engine even work or is it a gradual thing and how would it relate to gas mileage? I've been experiencing what I would consider low gas mileage, it's within the range of a Reatta (18-29) but always seems to like to stay under 20 even after a decent long range highway drive. It doesn't idle as smoothly as it should when it's warmed up as well. It's also quite possible that I'm just a perfectionist and not familiar enough with my car yet to note it's nuances, but it just doesn't seem like it's running as well as it should be. Thanks for the help, I'll keep ya posted. -Dan Link to comment Share on other sites More sharing options...
2seater Posted January 13, 2004 Share Posted January 13, 2004 It's good to hear the trip went well, and you may have eliminated one item as the problem. A bad or lazy O2 sensor is usually the cause of poor mileage, but a misfire would tend to confuse the sensor also. Link to comment Share on other sites More sharing options...
padgett Posted January 13, 2004 Share Posted January 13, 2004 Have you read my article ?I have seen ignition problems act like almost anything but what you are experiencing certainly sounds like a failing coilpack. If you have a local Pick-a-Part just go looking for a late Delco coilpack/ESC on a 3800. Takes a 7mm socket on the wide connector and a 7/16" box for the three nuts under the bracket then the whole assembly just lifts off and is a bolt-in replacement for a Magnavox.Is something that is always good to have a spare since if the ESC dies, so does the car. Link to comment Share on other sites More sharing options...
Guest imported_dantm4 Posted January 14, 2004 Share Posted January 14, 2004 I did read your article Padgett and the O2 sensor has been in the back of my head for a while to replace. I'd like to replace as much on the car as possible (within reason - maintenance) since I think it's in otherwise good shape. Since I've had the car for three months I'm learning as much as I can since I'm not very familiar with it. As always everyone's advice is invaluable - may be a while before I can replace things but I'm working on it. There are actually a couple junk yards nearby but it's a process I've never gone through. How much would the coils and mounting plate set me back as I'm not the richest guy in the world but would like my Reatta to run in tip top shape. The O2 sensor is on the agenda, but I'm having some problems with my other car (vibration above 60, but seems more like a CV joint, rotor, or out of balance wheel as the suspension isn't as robust as the Reatta's) and I feel that's more serious to address since the Reatta is my "fun car" and would like to keep the mileage as low as possible. Thank you all again, I'll keep ya posted.-Dan Link to comment Share on other sites More sharing options...
Guest Albert Posted January 14, 2004 Share Posted January 14, 2004 I had a Front end vibration on a 90 Chev a number of years ago, and found that by touching the brake it went away. With some more diagnostic work i did a compression test, and found one cylinder a little odd. When i pulled that side valve cover the push rod had gone through the rocker, but the motor still ran good on 5 cylinders. I have had problem with my 88 pont tempest not always unlocking the clutch, cheap solution pull the wires off the tranni with over 265,000 on a 4 cyl I figured it was not any more work as it has pulled some heavy loads, even a 54 Packard 500 miles without a problem. Link to comment Share on other sites More sharing options...
padgett Posted January 15, 2004 Share Posted January 15, 2004 Every yard de junque has a different idea of how golden a part is. Best is if you know somebody there. Next best are usually pick-a-parts. Next are the yards where you can go back and get the parts yourself. Then come the ones that don't allow anyone in back. These are the most expensive.I would expect to pay between U$5 and U$25, possibly up to $40 if the only one in town and was guarenteed for 30 days but then I know a few people and am cheap.Two things: always ask the price *before* you go back - ignition and coil assembly for a 92 or later 3800 - (unless you know the people well) and be ready to leave if they start pricing the pieces. Link to comment Share on other sites More sharing options...
Guest imported_dantm4 Posted January 15, 2004 Share Posted January 15, 2004 Wow, that's not much at all, $40 at most for the coils and the mounting plate?-Danp.s. I can think of at least three within about 5 minutes of my apartment, and no I don't live in a bad part of town....just happen to live near the river and I guess the yards de junque like to congregate there. Link to comment Share on other sites More sharing options...
padgett Posted January 16, 2004 Share Posted January 16, 2004 That is the most I would pay, not necessarily what someone would want. Fortunately it has no core value. All depends on the yard. Good news is the ten year point is where dull cars tend to begin to reach the yards. Link to comment Share on other sites More sharing options...
Guest DTerry Posted January 16, 2004 Share Posted January 16, 2004 Correct me if I'm wrong, but doesn't the torque converter lock disengage when you step on the brake? Sometimes mine will feel like it's surging while coasting downhill, which I think is caused by the lockup. Not often, but occasionally. If I step on the brake just enough to turn on the brake light, it goes away, which leads me to believe that if it were happening during cruise I could check it the same way. Right? That said, I suppose if it were a wiring problem (as in an unintended ground), it wouldn't disengage at all, and the engine/drivetrain connection would be hardwired. But...if that were the case, would you be able to start the car and get underway to begin with? If the ground was made for lockup, wouldn't it be engaged even before going into closed loop? Link to comment Share on other sites More sharing options...
Guest Albert Posted January 16, 2004 Share Posted January 16, 2004 yes the torque converter is suppose to unlock with the brake pressed, to disangage both the converter and the cruse control. Link to comment Share on other sites More sharing options...
padgett Posted January 16, 2004 Share Posted January 16, 2004 TCC also unlocks when the TPS senses less than 2.5% (e.g. when you take your foot off the gas unless in cruise). Should have no effect when coasting if everything is reading correctly (TPS at idle should read between .38 and .44vdc & over 4v at WOT). Link to comment Share on other sites More sharing options...
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