Transmission issues

reif · #1 (**permalink**) 01-08-08, 12:35 PM

ok, so my girlfriend's 01 catera is having some issues with the transmission.
we were driving back from a our winter vacation going ~70mph on the highway when the sport mode light turns on and all the gear indicator lights on the gear selector turn on, the car didn't seem to suddenly downshift or have any immediate issues. we pulled off to the side of the road and turned off and restarted the car, the sport light was off now, but all the indicator lights were still lit up. the first time we tried to accelerate the care hesitated to go into second, only getting there with a substantial clunk which triggered the blinking sport light again. since then the seems to shift up smoothly (though the sport light will start blinking the first time the car shifts gears) but it will not shift down unless the gear selector is moved to one of the three manual gears.

she took the car to a mechanic (not a Cadillac specialist) who seems to think a brake sensor is causing this issue, which seems really off to me.

from what I've read here, and experienced on my own car it seems to me that it would be and issues with low or fouled transmission fluid (hasn't been changed in ~90k miles

), the TCM, or the PRNDL sensor. this car seems a lot more complicated than the 20+ year old cars I'm used to working on, so I'm kind of doubting myself

Am I right in my thinking? is there a known issue with some braking component causing this sort problem (maybe abs speed sensor?), or is there something else I haven't considered yet?

any help would be appreciated

dwheeler · #2 (**permalink**) 01-08-08, 07:40 PM

I don't know if there is a brake sensor relation to the transmission, but my 97 just did the same thing. I have a code reader and it said that a transmission component slippage. I was going to check the fluid but can't find a dipstick for it. I was going to hope that changing the fluid might help, but I do fear that it will turn into another big ticket fix.

MyOpel · #3 (**permalink**) 01-08-08, 08:20 PM

Just had this happen on my car. Go to a place that will scan the codes for free, they will probably tell you it's PO705 Automatic Transmission Manual Shaft Shift Position Switch AKA PRNDL sensor. If you live in Canada $410 just for the part, I got it from SPDC for about 150. Dont drive the car much until this is fixed.

BackStreet · #4 (**permalink**) 01-09-08, 04:31 PM

Quote:

Originally Posted by dwheeler

I don't know if there is a brake sensor relation to the transmission, but my 97 just did the same thing. I have a code reader and it said that a transmission component slippage. I was going to check the fluid but can't find a dipstick for it. I was going to hope that changing the fluid might help, but I do fear that it will turn into another big ticket fix.

There is no dipstick on a CAT but there is a fill/overflow hole.

All you have to do is jack up the car on that side, remove bolt, squirt in fluid, put a pan under, jack down to remove extra fluid, jack up to put bolt back.

Way easy on a lift. Just fill to bottom of hole.

passionaterage · #5 (**permalink**) 01-09-08, 06:17 PM

Thats a good way to add the fluid and get it the right level, just be sure the car is at operating temperature and RUNNING (in park of course) when you do all that. Some people may not know that and just do the "jack-up-add-fluid" thing and wayyyy too much will run out, causing the level to be WAY low. Just thought it should be clarified.

PEETYZ · #6 (**permalink**) 01-10-08, 04:42 PM

you could change fluid and add a bottle of lucas tansmission fix use whole bottle of lucas and mix in fluid till full Lucas will renew worn bands and helped my transmission but you will hear mixed thoughts about it but first check fluid level and change/add accordingly best of luck

reif · #7 (**permalink**) 01-11-08, 07:31 PM

well heres an update:
she ended up moving the car to a transmission specialty shop nearby, it turns out the transmission is pretty much shot. the fluid basically got so bad it managed to cake everything up. but a new tranny(used) is in there, and everything seems to be working, fine, but the car is going to stay under the mechanics observation till the end of the weekend.

so thats going to be a lesson well learned, never forget the transmission fluid.

KateraK · #8 (**permalink**) 01-12-08, 01:56 PM

I have a 1998 catera and I had the same problem, and I too replaced the tranny, and it did fix it.
BUT now its happening again and I thought noooo it cant be another bad tranny!!!! So i looked at the connectors on and around the tranny housing. They were a little oxydized so I cleaned them out and now it shifts just fine and is back to normal, so I looked at the tranny i replaced and it is still good, just a dirty connector.
My two cents.
my ABS and TCS and check engine light are still on though and I have no speedometer still but the tranny still shifts good in drive at least.
BTW I have went through school for automotive repair and received a degree but no longer work on cars for a living, so I pretty much know what im doing, just dont always know the problem lolz.
but anyway i hope this helps someone, dont forget dielectric grease on all connectors!

edit

eastsidercaddy · #9 (**permalink**) 01-12-08, 10:48 PM

to fix the ABS/TC light you may want to look at replacing the fuse. I have a switch wired to my fuse, so when it rains i can burnout and do doughnuts. If that's not it then don't worry about it.

KateraK · #10 (**permalink**) 01-13-08, 12:07 AM

I have a TCS button that is factory i can press so i can burnout but my complaint is that my speedo doesnt work, im pretty sure its the EBTCM though ima check er out tomorrow prolly