Having an issue with a GS450H that has a P2797 code. Which says oil pump controller malfunction. I read another post that said this is a 3k part from Lexus, but it can be rebuilt. My question is, has anyone had success removing this oil pump and having it rebuilt at a machine shop? Also, do I have to drain the trans fluid to remove this unit? If so, how do you drain and refill the trans since there isn't a dipstick. Are there fill and drain plugs on the side of the transmission case.

Any advice or how to instructions would be greatly appreciated.

Thanks!

 

I know it’s years later but were u able to deal with this. I have same issue.

 

There are 2 plugs, one for drain one for fill. You need to drain oil before open that pump.
For removing that pump, is easy operation, only few screws. There are 2 problems with that pump : electric motor bearings , which are inexpensive and relatively easy to replace, and/or hydraulic pump itself ( can be noisy, or cannot build enough pressure). In this case , good luck finding someone for rebuild. You can buy a used one too.

 

this job took me 4 weekends to complete and i still occasionally get the error code. yes you have to drain trans fluid. its a PITA but its fixed and running. used part on ebay is 1.5k or a new one was like 3k. replaced the 2 bad bearings for $80 in parts