: Transmission and code...



Eric2203
11-07-04, 07:44 PM
Hi all,

I'm new here. Seems like a nice forum. :)

I recently bought a 1996 DeVille with 93K miles on it. 95K now. I have had the Service Transmission message ever since I bought it. I was told the sensor was faulty and that nothing was actually wrong with the transmission. I trust the salesman for reasons I won't get into, but it's not an info he found out for himself. He had the car checked and was told that. So I don't know how reliable this is.

Having found out about OBD2, I ran the codes and got PC0717 CURRENT. Err... ok, am I supposed to read that as P0717 (Input Speed Sensor Circuit Low Input) ? So what does the C mean in my message ? And what does the actual message mean ? Because that's rather unhelpful to me... Does it mean it's really just the sensor being bad or is there something worse going on here ? The only other info I can supply is that the car drinks oil quite heavily but after reading some posts here, that's normal ? I drive 60 miles a day if that's any help...

I'm not exactly a specialist when it comes to cars, so bear with me, LOL. Thanks in advance for any help.


Eric

chazglenn3
11-07-04, 08:36 PM
The input shaft speed sensor is buried deep within the transmission and as a result expensive to repair. The PCM defaults to a set value when the data from the sensor is unavailable (PC0717 code set) and shifts much harder than it should. I get the code every once in a while, but have been able to just clear the code and the car drives fine. Yours sounds more like a hard failure or hard wiring problem. Clear the code and see if it comes right back.

Eric2203
11-07-04, 09:35 PM
Thanks for the reply. The car doesn't shift harder than it should. It seems fine. So I followed your advice and cleared the code. It did not come back. I restarted, put it in gear, back into Park. I haven't actually driven anywhere. Nothing comes up. I'm hoping it means it's all good. If so, how come I've had that appear for the past month ? Doesn't it go away by itself if all's good ?

chazglenn3
11-07-04, 10:15 PM
I think I read somewhere that it takes 60 start cycles to clear a code. Maybe you just hadn't gotten that many starts yet. Glad to hear that it may be okay! :cheers:

BeelzeBob
11-07-04, 10:33 PM
Thanks for the reply. The car doesn't shift harder than it should. It seems fine. So I followed your advice and cleared the code. It did not come back. I restarted, put it in gear, back into Park. I haven't actually driven anywhere. Nothing comes up. I'm hoping it means it's all good. If so, how come I've had that appear for the past month ? Doesn't it go away by itself if all's good ?


The diagnostic codes continually check the situation. If the code was "current" then it was setting every time you drove the car.

Just starting the engine and idling is not enough to run the diagnostics for the input speed sensor code. I suspect that when you drive it the code will reappear.....

96 STS
11-08-04, 12:59 AM
Bbob is right. The code will most likely reappear at some point. Depends on how faulty your sensor is. I think the speed criteria is >7 MPH. Once your car is traveling greater than 7 MPH, if it senses incorrect voltage from this sensor then a code will set.

chazglenn3 is also correct in that you can continue to clear the code & keep on driving. But, how long your car will continue to shift correctly is anyones guess. Mine eventually came up so often & my trans began to engage so rough that I eventually repaired it myself.

If your mechanically inclined, check out this webite & read the write-up about this repair. I followed the instructions to the "t" & it went very well. www.caddyinfo.com

If not inclined, get several estimates & look for a mechanic w/ 4t80e experience. It's really not that difficult, but the engine/trans must be dropped to get access to it, hence the high price. The sensor itself only costs about $25. Sucks, I know. It's all the labor involved that your paying for.

My estimates ranged from $800 to $1200 if I remember correctly. Again, shop around & you should be able to find someone that can do this for well less than $1g.

Good luck & keep us informed.

Cheers,
96 STS

Eric2203
11-08-04, 07:38 PM
Bbob, you were right. As soon as I actually got the car to move, it re-appeared. Guess I'm in for a repair...

I don't clear the code all the time, I leave it as it is. It still feels fine now. I just can't afford the repair right this very minute. I was pondering waiting for the 100k miles service, but that may be too long to wait for the repair if it makes the car shift more roughly.

I'm not exactly mechanically inclined. And I don't really want to ask people who are to do it just to save money because I tend to be picky about such things. I'd rather have it done by someone who knows what he/she is doing. But that's just me...

Thanks very much for the replies.


Eric