'03 S80 ETM failure?

[Quinn]

So here is the deal. My battery pooped out on me so i replaced it. She still wouldn't start, just turned over and over. So i had it taken to a local shop in my small town. Well they replace the fuel pump and now they got it started. But message says 'reduced engine performance' and wont run higher than 1800 RPM or so. The garage was not equipped to diagnose so they had to walk away from it. So i had them tow it back to my house. Now its cold out and when i start it, it revs high like normal for about 10 or 15 secs and during that warm up, it runs smooth. But when warm up is done and RPMs return to normal then i have a very rough idle.
I have researched my condition and it seems to point to my ETM. I contacted XemodeX and they say they cannot provide service for my ETM for that model and year. Not sure what I can do at this point?

[precopster]

I doubt you have a Magnetti Marelli ETM. This model year points to a Bosch unit which are driven directly by the ECM (engine control module)

The Bosch throttle body has contact sensors which may have failed but this is indeed rare with this model year.
Can you provide the engine type (either B5204T or B5244T or B6284T or B6294S) Is it turbo?

You are certainly stabbing in the dark without having codes read. Use either a Autel EU702 or or US703 series scanner to have codes read.

If when cold the motor behaves normally the problem is pointing more toward oxygen sensors.

[Quinn]

I opened up the ETM and inspected the contacts and reassembled. The car starts and idles smooth and is drive-able but the "reduced engine performance " message still remains and I cant rev the engine higher than 35oo RPM. I scanned and retrieved codes P2135, P0638, P2721, P3501. It is a non turbo 2.9 with a 92 in the VIN which is a B6244F engine.