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30K views 60 replies 33 participants last post by  jadcock 
#1 ·
75,000 kms on a 99 seville.
The in-dash transmission life monitor has not budged off 100% since the car was put on the road. However, there are no codes stored in any of the modules. I can't find a bulletin dealing with this either. I will be changing the transmission fluid at 83,000 kms. Anyone else with the same problem?
Just curious,

Dave :coolgleam
 
#28 ·
The Eldorado readouts do not mention anything about the tranny fluid life. I think it is a '98 and up Seville option.

I never saw the purpose of changing the tranny fluid even at 100,000 miles. A neighbor of mine who owns a Gabralter transmission shop even said that it's not necessary for many transmissions - mainly GM transmissions. On the other hand he mentioned that Ford transmissions are completely different and that they require more attention.

Anyways, I'd just leave it alone. Don't waste your money or tempt fate!
 
#29 ·
cl1986 said:
Hmm, why would a rental have less life left?? Have you ever seen someone driving the "rental". That about says it all.
The fact that the Deville is a rental, standing alone, cannot explain the discrepancy my friend.

First, this particular Deville had less than 9K on the clock. It is a rental used by the dealer and it is driven mostly by blue-haired old ladies. No way they are going to engage in brutal, constant, WOT driving. No way.

Second, a lot of the Sevilles that show 100% tranny fluid life after 30k, 50K, 60 or 70K miles on the clock HAVE been driven hard, or on stop and go situation where you would expect the computer to start counting down.

I think that there is something particular to the Seville tranny fluid life computer that keeps the reading at 100% life, even after extended, harsh driving.

Neither my dealer, nor anyone here, has been able to give me a completely satisfactory answer.

Maybe some of the forum members who have same-year Devilles can chime in here with their experience.

Personally, I am not too concerned. I will just follow the manual's recommendations and have the fluid changed at 100k miles.

But the fact that the Devilles were rentals is not a satisfactory answer. :tisk:
 
#30 ·
1toycad said:
The fact that the Deville is a rental, standing alone, cannot explain the discrepancy my friend.

First, this particular Deville had less than 9K on the clock. It is a rental used by the dealer and it is driven mostly by blue-haired old ladies. No way they are going to engage in brutal, constant, WOT driving. No way.

Second, a lot of the Sevilles that show 100% tranny fluid life after 30k, 50K, 60 or 70K miles on the clock HAVE been driven hard, or on stop and go situation where you would expect the computer to start counting down.

I think that there is something particular to the Seville tranny fluid life computer that keeps the reading at 100% life, even after extended, harsh driving.

Neither my dealer, nor anyone here, has been able to give me a completely satisfactory answer.

Maybe some of the forum members who have same-year Devilles can chime in here with their experience.

Personally, I am not too concerned. I will just follow the manual's recommendations and have the fluid changed at 100k miles.

But the fact that the Devilles were rentals is not a satisfactory answer. :tisk:
I agree!
With only 9K miles on the clock, and if it was dogged half of those, the indicator should be at 100%. It is far less likely the car was dogged at all. Rental is not conclusive evidence of anything, other than more than one driver. A single algorithm error is far less likely than a fault. The most likely of all scenarios is that the mileage was incurred quickly from the time it was put into service, meaning that the accumulated mileage from zero to 9K was faster than normal. The computer does not keep track of time with just a clock or calendar, but it does count "run" cycles. A run cycle is start/run/cool-down. If the span of run cycles and miles do not match what is in the "normal" algorithm table, then the % will count down. The possibility is therefore conceivable one car may expire the predetermined life span early, while another is still at 100% at over 100K miles. Thus defining, the importance to follow the manufacturers' recommendation for fluid changes.
 
#31 ·
1toycad said:
The fact that the Deville is a rental, standing alone, cannot explain the discrepancy my friend.

First, this particular Deville had less than 9K on the clock. It is a rental used by the dealer and it is driven mostly by blue-haired old ladies. No way they are going to engage in brutal, constant, WOT driving. No way.

Second, a lot of the Sevilles that show 100% tranny fluid life after 30k, 50K, 60 or 70K miles on the clock HAVE been driven hard, or on stop and go situation where you would expect the computer to start counting down.

I think that there is something particular to the Seville tranny fluid life computer that keeps the reading at 100% life, even after extended, harsh driving.

Neither my dealer, nor anyone here, has been able to give me a completely satisfactory answer.

Maybe some of the forum members who have same-year Devilles can chime in here with their experience.

Personally, I am not too concerned. I will just follow the manual's recommendations and have the fluid changed at 100k miles.

But the fact that the Devilles were rentals is not a satisfactory answer. :tisk:
Geno gave us a satisfactory answer.
Computer changed tranny fluid life reading only if temperature is higher than normal. That is it. If rental car with 9K miles has less than 100% of transmission oil life it just means one or some of next possibilities: 1. Somebody drove that car and transmission temperature was pretty high for some reason;:eek: 2. Somebody overwrited computer' data;:confused: 3.PROM was changed;:rolleyes: 4. Somebody read engine oil life reading instead of transmission oil life.:sneaky:

These rental cars were driven by somebody else. So, we can't say for sure about anything.
 
#32 ·
I agree that one should be careful with "power flushing" trans fluid with the highly advertised services.

There have been numerous claims of power flushing correlating with trans failures. Some say you can dislodge dirt and contaminants that then circulate through your trans and cause damage. Others say the oil change shops are not staffed with properly careful techs and so dirt from your fittings and/or contaminants from others' trashed trans ends up pumped into your trans.

My 98 STS shows 100% trans oil life at 58,000+ miles and I'll leave it alone.

On my older cars, I drop the pan, drain as much trans fluid as possible, and change the 'filter'. This gets out about 1/2 the old fluid. Then I drive it a week or so and, using a vacuum oil pump (about $75 from Griot's Garage), suck the trans oil out through the trans dipstick tube and replace the trans oil again. This is tons faster and easier than removing the pan again. Pull out the fluid another week or so later and you've got a high percentage of fresh trans oil.
 
#33 ·
Maybe Mr. Castellano. will show up here to shine a bright light on the reality again.

My '98 Seville displayed 100% oil life when I changed the fluid at 125,000 miles.

My '04 Deville displays 98% oil life at 3,600 miles.

Perhaps the algorithm has been fine tuned over the years?
 
#34 ·
oldgamer said:
Geno gave us a satisfactory answer.
Computer changed tranny fluid life reading only if temperature is higher than normal. That is it. If rental car with 9K miles has less than 100% of transmission oil life it just means one or some of next possibilities: 1. Somebody drove that car and transmission temperature was pretty high for some reason;:eek: 2. Somebody overwrited computer' data;:confused: 3.PROM was changed;:rolleyes: 4. Somebody read engine oil life reading instead of transmission oil life.:sneaky:

These rental cars were driven by somebody else. So, we can't say for sure about anything.
The algorithm that calculates oil life expectancy is a complicated computation that takes into effect many different criteria. Oil temperature is one such factor in the calculation. My post was intended to point out that no one criterion is a leading factor, all table criteria are calculated. It is much easier to follow the manufacurers' fluid change recommendation for your particular driving conditions. Should your vehicle indicate a fluid change sooner than expected, it would be wise to investigate the reason after the fluid change.
 
#35 ·
Res STS said:
I agree that one should be careful with "power flushing" trans fluid with the highly advertised services.

There have been numerous claims of power flushing correlating with trans failures. Some say you can dislodge dirt and contaminants that then circulate through your trans and cause damage. Others say the oil change shops are not staffed with properly careful techs and so dirt from your fittings and/or contaminants from others' trashed trans ends up pumped into your trans.

My 98 STS shows 100% trans oil life at 58,000+ miles and I'll leave it alone.

On my older cars, I drop the pan, drain as much trans fluid as possible, and change the 'filter'. This gets out about 1/2 the old fluid. Then I drive it a week or so and, using a vacuum oil pump (about $75 from Griot's Garage), suck the trans oil out through the trans dipstick tube and replace the trans oil again. This is tons faster and easier than removing the pan again. Pull out the fluid another week or so later and you've got a high percentage of fresh trans oil.
Although your system is good, it is much easier to unfasten the high pressure transmission cooling line and use the pump in the transmission to do the work for you. Adding fresh as you are pushing spent.
 
#36 ·
oldgamer said:
Geno gave us a satisfactory answer.
oldgamer said:
Computer changed tranny fluid life reading only if temperature is higher than normal. That is it. If rental car with 9K miles has less than 100% of transmission oil life it just means one or some of next possibilities: 1. Somebody drove that car and transmission temperature was pretty high for some reason; 2. Somebody overwrited computer' data; 3.PROM was changed; 4. Somebody read engine oil life reading instead of transmission oil life.



These rental cars were driven by somebody else. So, we can't say for sure about anything.






With all due respect, your post makes no sense to me.


1. Somebody drove that car and transmission temperature was pretty high for some reason;

I should have made it clear. I have driven more than one rental Deville. Mileage ranged from less than 9K to less than 18K. Every single Deville showed less than 100% tranny fluid life. It is just not possible that each one of those Devilles was driven by a Mad Max wanna be who fried the tranny fluid. Also, remember that the other poster here also drove a rental Deville that showed less than 100% tranny fluid life. One Deville may have been driven harshly. Maybe two Devilles could have been driven harshly. But three? Four? Five? That is too many Devilles to be a mere coincidence. Also, look at JimD’s post. His ’98 Seville showed 100% tranny life when he had the fluid changed at 125K miles. On the other hand, Jim’s Deville with less than 4K miles already shows less than 100 tranny fluid life. I just cannot believe that Jim would drive the hell out of his Deville while babying the Seville. It just makes no sense.


2. Somebody overwrited computer' data;


On five or six different Devilles? Possible, I guess, but not probable.


3.PROM was changed


See comment to #2 above. Again, not probable.


4. Somebody read engine oil life reading instead of transmission oil life.


I suppose, but that means that JimD, the other poster (can’t remember his name now) and myself all made the exact same mistake and confused oil life with tranny fluid life. The chances of three different people, who are familiar with these cars, making the same mistake are not very high.


And finally--Geno gave us a satisfactory answer.


I agree that Geno Castellano is usually right on track with his advice. This time his explanation makes no sense because of the wildly differing results from Devilles and Sevilles.


I think that at the time when GM made “our” generation of Sevilles it was really pushing the concept of low maintenance costs. I have the original sales brochure for my Seville and “low maintenance” was a big item. Maybe by the time that GM got around to the current Deville generation that concept was not that all important, hence the change in the computer’s algorithms. That is the one explanation that makes sense to me.


Since the Sevilles were advertised as the “sports sedans” in Cadillac’s stable I’d have assumed that GM would have rigged the computer to be more “sensitive” but maybe I was wrong.


As JimD previously mentioned, forget the computer and change the tranny fluid pursuant to the owner’s manual recommendations. That works for me!
 
#37 ·
91TexasSeville said:
Although your system is good, it is much easier to unfasten the high pressure transmission cooling line and use the pump in the transmission to do the work for you. Adding fresh as you are pushing spent.
Good idea.

BTW, I used to own a 1989 Seville, black on black. I really liked that boxy body style.

When I was younger I also wanted to own a Gran Torino. That was such a hot car when I was in in Jr. High. (still is, I imagine)
 
#38 ·
1toycad said:
With all due respect, your post makes no sense to me.


1. Somebody drove that car and transmission temperature was pretty high for some reason;

I should have made it clear. I have driven more than one rental Deville. Mileage ranged from less than 9K to less than 18K. Every single Deville showed less than 100% tranny fluid life. It is just not possible that each one of those Devilles was driven by a Mad Max wanna be who fried the tranny fluid. Also, remember that the other poster here also drove a rental Deville that showed less than 100% tranny fluid life. One Deville may have been driven harshly. Maybe two Devilles could have been driven harshly. But three? Four? Five? That is too many Devilles to be a mere coincidence. Also, look at JimD’s post. His ’98 Seville showed 100% tranny life when he had the fluid changed at 125K miles. On the other hand, Jim’s Deville with less than 4K miles already shows less than 100 tranny fluid life. I just cannot believe that Jim would drive the hell out of his Deville while babying the Seville. It just makes no sense.


2. Somebody overwrited computer' data;


On five or six different Devilles? Possible, I guess, but not probable.


3.PROM was changed


See comment to #2 above. Again, not probable.


4. Somebody read engine oil life reading instead of transmission oil life.


I suppose, but that means that JimD, the other poster (can’t remember his name now) and myself all made the exact same mistake and confused oil life with tranny fluid life. The chances of three different people, who are familiar with these cars, making the same mistake are not very high.


And finally--Geno gave us a satisfactory answer.


I agree that Geno Castellano is usually right on track with his advice. This time his explanation makes no sense because of the wildly differing results from Devilles and Sevilles.


I think that at the time when GM made “our” generation of Sevilles it was really pushing the concept of low maintenance costs. I have the original sales brochure for my Seville and “low maintenance” was a big item. Maybe by the time that GM got around to the current Deville generation that concept was not that all important, hence the change in the computer’s algorithms. That is the one explanation that makes sense to me.


Since the Sevilles were advertised as the “sports sedans” in Cadillac’s stable I’d have assumed that GM would have rigged the computer to be more “sensitive” but maybe I was wrong.


As JimD previously mentioned, forget the computer and change the tranny fluid pursuant to the owner’s manual recommendations. That works for me!
I didn't noticed you talking about differences in Deville and Seville readings. My fault. You right, may be algorithm was changed later. But it still sounds strange for me that almost everybody post 100% transmission oil life and these four rental cars from the same dealer have different results.
 
#39 ·
oldgamer said:
I didn't noticed you talking about differences in Deville and Seville readings. My fault. You right, may be algorithm was changed later. But it still sounds strange for me that almost everybody post 100% transmission oil life and these four rental cars from the same dealer have different results.
Oldgamer: They are not rentals from the same dealer. My rental Devilles came from different Enterprise offices.

JimD's Deville is his own personal car.

The poster rented a Deville from another, different dealer. The Devilles all come from different places.
 
#40 ·
Alright fellas I am going to assume that the sensor on the atf is the same as the oil in that in the service manual it says it is based on conditions such as temperature and driving conditions. So to those of you that want to change your fluids before they need to be done go for it such as those of you still changing your oil every three thousand and I can stand behind this because I recently sold my 94 STS for a 99 and that car was driven until it said to change oil usually 4-5000 miles per oil change and it has 189000 and still going strong it all depends on the conditions and that is what these sensors are based on. So if you want to go out and change your fluids early go for it your not going to hurt anything but you don't really need to unless the gauges say too. And to those of you driving eldo's from the same years I don't know when gm put the tranny fluid life sensor in if ever they really neglected the eldo as far as upgrades.
 
#48 ·
In my 95 SLS it had 110,000 miles on it when I brought it. No fluid change on the transmission till it told me too which was around 150,000 miles. The DIC said change trans fluid. I eventually changed it but I never had a problem with the fluid again and now I'm at 165,000 miles.
 
#55 ·
I just wanted to post my experience with the tranny fluid issue. I have a 99 Seville STS, 80,000 miles in it, and the tranny fluid life monitor is still at 100%. So I take it to the mechanic and tell him to check it and clean it if needed (among other things the car needed). I call back and he said it needed flushed out. After he did it, I checked it and the fluid looks cleaner than before. I think after that many miles one should change the tranny fluid. It's more of a preventative maintenance issue for me.
 
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