EnclaveForum.net: Buick Enclave Online Community banner
1 - 5 of 5 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
2008 Buick Enclave CXL FWD

I had the low pressure transmission codes so I removed the TCM and all 4 pressure switches were broken. I replaced them with a Sonnax pressure switch kit and buttoned it up. Fluid level is on the mark.

I'm getting p0873 and p0990 codes now and the shift from 1st to 2nd is very late. Between 3-4000 rpm unless I accelerate very slowly. There is no hesitation when I shift into reverse or drive and the other gears seem to shift fine. When I use the "L" gear I can manually shift to 2nd with no delay/lag. Only happening in drive. Searching the web, I might just be the first person ever to get this code. Can't find any info on the cause or repair besides it being high pressure.

Maybe the transmission needs a relearn? idk

Appreciate any help.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #3 ·
"The P0873 trouble code refers to a detected anomaly in the transmission fluid pressure. The reported pressure has fallen beyond the manufacturer's set parameters."

"In a P0873, the sensor in the transmission system's C circuit has detected a pressure level that extends beyond the manufacturer's set limits."


It's a very generic write-up and a little contradicting. I was hoping to find someone who dealt with this code specifically and what the fix was. Thank you tho.
 

·
Registered
Joined
·
14 Posts
I'm going to say that something didn't go back together properly during the reinstall. Missing or damaged o-ring somewhere?
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #5 ·
I found an old TSB issued by GM saying the possible cause is debris in one of the holes (#29 or something) in the separator plate which is in the valve body. Which is behind the TCM.

Maybe small pieces of the old pressure switches idk.

Question now is can the valve body be removed without dropping the transmission? ugh

This truck man...Fix one thing, 2 more things break.
 
1 - 5 of 5 Posts
Top