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No TCC lockup any time


amcars

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My 93 Seville N*transmission has no TCC lock up, otherwise it shifts smoothly trough all the gears. Soon after going on the highway the service engine light comes on and if I check the codes while driving, there is PO39 current.

I can't feel TCC lock up either in the 3rd or 4th gear. I was thinking that maybe it is the TCC solenoid. What is the talk about some new prom? Could it fit my case? Where can you get it and for how much?

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The easiest way to check it out is maintaining constant speed (say 50-55) with your right foot and touching the brake pedal with left one to engage the brake switch. RPMs should jump some 150-200 during that procedure. If it does not happen yor VCC does not operate properly for some reason.

The saddest thing in life is wasted talent

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I have done that like the topic says, no lock up - 18000 miles(2,5yrs) ago new rebuilt TC and all new solenoids according to the previous owner's records. Still would like to know about PROM

If your problem is deep inside of tranny (possible) you could just drive like that. Sure your fuel economy will drop by some 10-15%, but it is less than you would spent on tranny expensive repair.

The saddest thing in life is wasted talent

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Personally, I would not recommend running with the TCC inoperative like that. It will reduce your fuel economy, but more important in the short term, it will increase your transmission fluid temperatures drastically, especially on long runs. You could really cook the transmission fluid if left like that for a long time. The size of the tranny cooler, etc, on the car is designed with an operative TCC in mind. If this is malfunctioning, you could ruin more than just your fuel economy.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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Personally, I would not recommend running with the TCC inoperative like that.  It will reduce your fuel economy, but more important in the short term, it will increase your transmission fluid temperatures drastically, especially on long runs.  You could really cook the transmission fluid if left like that for a long time.  The size of the tranny cooler, etc, on the car is designed with an operative TCC in mind.  If this is malfunctioning, you could ruin more than just your fuel economy.

Makes sense, but I remember our GURU addressed this problem some time ago and never mentioned posssible damage to tranny. Lock'up mode is primerily designed for better fuel economy. Cheking the ATF regularly and probably draining and refilling it once a year (without dropping the pan) would not hurt either. I would avoid by all means expensive repaires on high mileage or old cars since yo never know what will fail next, but it's me. smile.gif Besides, taking car to a tranny shop is always a risky business, if you ask me. A poll showed that only 10% of our Caddys have more than 175.000 miles. I always keep that number in mind, since it is statistically proven.

The saddest thing in life is wasted talent

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Cheking the ATF regularly and probably draining and refilling it once a year (without dropping the pan) would not hurt either.

If I was running without the lockup feature, I would definitely drain the fluid at least once a year...especially if running on the Interstate a lot (where lockup is normally achieved, and heat will build up if inop).

A TCC solenoid is relatively easy to replace and not invasive, if that is the problem. TCC solenoids are relatively common repairs on older transmissions. The solenoid simply wears out, as all mechanical parts will do. I'm not familiar with code P039, but I'm sure we've seen it here before; a search on that code will likely turn up a lot of suggestions for repair.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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What is the tranny type of my -93 Seville 4T80 or 4T60?

As ADALLAK said, if it's a Northstar, it's a 4T80-E. If a 4.9L, I believe they came with a 4T65-E.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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It sounds like we are having exactly the same problem with our car. First of all - I am NOT suggesting anything - we know nothing!! After saying that, I'll tell you how to find the information that I read. Click on "Caddy Info Home Page" at he top left of this page. Then click on "How-To" at the top of that page. Scroll down to transmissions, click P039. There ya go.

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It sounds like we are having exactly the same problem with our car. First of all - I am NOT suggesting anything - we know nothing!! After saying that, I'll tell you how to find the information that I read. Click on "Caddy Info Home Page" at he top left of this page. Then click on "How-To" at the top of that page. Scroll down to transmissions, click P039. There ya go.

Did you try the lockup test? I would not bother to get new chip if the function works.

The saddest thing in life is wasted talent

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Cheking the ATF regularly and probably draining and refilling it once a year (without dropping the pan)  would not hurt either.

If I was running without the lockup feature, I would definitely drain the fluid at least once a year...especially if running on the Interstate a lot (where lockup is normally achieved, and heat will build up if inop).

A TCC solenoid is relatively easy to replace and not invasive, if that is the problem. TCC solenoids are relatively common repairs on older transmissions. The solenoid simply wears out, as all mechanical parts will do. I'm not familiar with code P039, but I'm sure we've seen it here before; a search on that code will likely turn up a lot of suggestions for repair.

TCC solenoid easy to replace - I guess it depends on the tranny type. Looks like in North* you must drop the whole tranny to do that. In 4.9 there may be enough room to take off the cover.

I agree with the guys who think that it is ok to drive without TCC, that's how the old transmissions used to be.

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I agree with the guys who think that it is ok to drive without TCC, that's how the old transmissions used to be.

Again, that's how the "old transmissions used to be" because that's the way they were designed, and the rest of the transmission cooling system was designed and sized accordingly. The transmissions were also larger, had larger sumps, had larger coolers, etc. Today's machines are so efficiently-designed that the proper operation of every component is essential to sustaining the life of the entire unit. The sump sizes and cooler sizes of today's transmissions are designed with an operational torque converter clutch in mind.

Jason(2001 STS, White Diamond)

"When you turn your car on...does it return the favor?"

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