: OSD says "Change Trans Fluid"



jss
07-17-06, 12:50 PM
I have a 94 Seville with 176k miles. Maybe 50k miles ago I did a transmission filter and flush. Recently the PCM went out and I replaced it (I put my old EEPROM in the new PCM). She sat for almost nine months until I could get around to determining the problem. Since putting in the new PCM (100 miles ago), the OSD gives me this message, "Change Trans Fluid".

1. Is there something I need to set/reset in the PCM? Are there sensors in the transmission that determine that the fluid needs attention, and I really do need to do another filter / flush?

2. She's running just like her old self (great). In the course of finding / fixing the problem I replaced both crankshaft position sensors (CPS). Is there anything that I need to do after replacing the PCM or CPSs?

Thanks, Jeff

clarkz71
07-17-06, 01:21 PM
You need to reset your trans oil life indicator............... OK I'll tell you. With the key on, hold down the off and rear defog buttons until the display says "Transaxle Oil Life Reset". Keep in mind that in another 50K you should change the fluid again and reset the indicator again, which you should do whenever you change the fluid.

mtflight
07-17-06, 02:03 PM
Check the fluid for a burnt smell. Overheating the fluid once (kinked line for instance) will cause the message to be displayed. Another fellow caddy owner accidentally kinked a line and the tranny became toast.

The Trans life indicator works like the oil indicator basically cycles and temperature... no blowby or combustion gasses though.

clarkz71
07-17-06, 02:22 PM
That's true, however I would hope he's already checked the fluid level and condition after getting the "change fluid messege". Did you??

jss
07-18-06, 09:07 AM
Gentlemen, thanks for the info. Yes, I checked the fluid level and condition and it looks good. What I didn't know was if 1)there was a sensor telling me that there was a reason to change the fluid and 2)because the message began the first time I started her up after replacing the PCM if there some PCM thing that needed to be done.

I'm not certain, but from the replies it looks like the answer to those questions are 1)maybe and 2)maybe?

As she's got 175k miles on the original transmission and as this fluid is about 50k miles old, I'll probably go ahead and do both; replace the fluid/filter and reset the transmission oil life indicator.

Thanks

mtflight
07-18-06, 09:18 AM
Gentlemen, thanks for the info. Yes, I checked the fluid level and condition and it looks good. What I didn't know was if



1) Is there a sensor telling me that there was a reason to change the fluid?

A transmission temperature sensor, yes, and the PCM decides when it's either had too high of a temperature (deteriorating the fluid) or enough hot cycles to merit a change. If the Transaxle life monitor was not reset when you changed the fluid originally then it's a "false alarm"


2)because the message began the first time I started her up after replacing the PCM if there some PCM thing that needed to be done.

This is hard to say because I don't know the history of the donor PCM, maybe that car needed a transaxle fluid change, or maybe yours is in a counter and because it was not reset when you changed it, then it thinks you need to change it. All speculation of what could have been.



As she's got 175k miles on the original transmission and as this fluid is about 50k miles old, I'll probably go ahead and do both; replace the fluid/filter and reset the transmission oil life indicator.

This is a good idea, anyway--can't hurt it. There's a new ATF out I think the number is a VI, and only available from your friendly dealer. I put that on mine when I exchanged it last.