Unusual ODBII codes not long after engine replacement
 

2008 RX8, had the engine replaced by the dealer under warranty about 2 months ago when the engine spontaneously nuked itself without warning. Bought the car about 11 months ago (second RX8) and had zero issues or trouble codes during that time, prior to the engine self destructing.

So as I said, that was about 2 months ago, and two days ago the check engine light came on while en route to a radiator shop to get the radiator replaced. He said he'd check the codes and clear them to turn the light off, but all he did was clear them without writing them down, so I had no idea what the problem was. Didn't drive the car yesterday, but today the check engine light came back on, and my cheap generic scanner is showing the following codes:

P0410 (may be an old code. I've researched this on the forums and have a good idea what the likely problem may be)

The ones listed below are the ones that I believe are new and that have me stumped. None of these were even listed in my OBDII manual that came with the scanner, nor did I find them in an online OBDII list. There's a web page though (obdii.pro) where you can enter the code and it finds the corresponding description. The descriptions I'm providing came from that site.

C0302 - Rear propshaft signal circuit low
C0702 - Level control accessory valve circuit malfunction
U0101 - Lost Communication with TCM

Do these codes mean anything to anyone, especially the three of them combined (possibly four if you include p0410)?

I'm probably going to have to take the car to the dealer, but I really don't like this dealer and prefer not to use them unless it's a warranty issue or something only MAZDA is really qualified to do. I'm sure they're going to try and charge me their full diagnostic fee too, regardless of the recent engine change under warranty.

Any help is appreciated, thanks.

None of those codes are relevant to the RX-8 except the loss of communication code and the P0410 which has to do with the air pump.

My guess is that you are using a crappy scanner.

............."and my cheap generic scanner is showing the following codes:"

Brilliant post, thanks so much for your help.

Get bent noob, I did help.

It looks like one of the plugs got bumped during the engine removal/install. I would reseat every connector going into the ECU, I would also reseat the ABS pump connector. Then clear codes and see if they come back.