Really needing some help with my 09 JCW clubman.
I've posted in 2 facebook groups and another forum with no help..

I'm getting code p12A3 on my autozone scanner
And codes 28b0 & 28A5 on my friends shop scanner.

It all started with my clutch fork. The fork snapped, the car sat for about 2 months until I fixed it. When I got it back together and started it I had an immediate limp mode with said codes.

I've tried different map sensors (both of them)
Cleaned the MAF and map sensors. Checked all my vac lines, pressure testes the system.

I'm not really coming up with anything!

I drive the car every now and then still, last week I was sitting in the McDonald's drive through, and limp mode chimed and popped up (which means it must have went away) and while waiting in line it went away and came back 3-4 times, then went away for a few minutes(McDonald's was busy lol), right before i pulled away with my food it came back.

The turbo is fine, no shaft play or excess oil,, if I run run car without the turbo inlet pipe I can see the impeller spinning..

Wastegate seems to be functioning fine and holds vaccume. (I checked all vac lines with a hand pump)

Changed the bypass valve. Still having issues.

I'm very much over this car currently, would love to start driving it daily again.

 

I would triple check that you didn't miss a hose connection during reassembly after the clutch job.

P12A3 - https://www.northamericanmotoring.co...ode-p12a3.html

28B0 is a fault with the diverter valve. The ECU could be holding this code thinking there is a problem with the diverter valve.
28A5 is the internal code related to the P12A3 code. There are two pressure sensors in the system: one in the intercooler pipe before the throttle body, and one on the intake manifold. These codes could be due to a loose pressure clamp between the turbo and the throttle.

 

I didnt disconnect any boost piping to take the trans out at all. So there would be nothing for me to "miss" on reassembly. And I pressure checked the system no leaks. I'll do another pressure check to be sure their is no small leaks, but its deffinitly not something as simple as a pipe I forgot to connect.

If I clear the code it comes back immediately. Without even trying to drive the car.

 

Those three codes you listed are related to a boost plausibility issue. The culprits are usually related to the diverter valve diaphragm, one of the pressure sensors (there are two - one on the intercooler pipe, and one on the intake manifold), or a boost clamp that's loose.

 

Alright. Il check again when I get off work tonight. But like I said I replaced both (the one on boost piping AND the one on the manifold) map sensors. As well as the bypass valve.

So hopefully when I pressure check again there is a leak somewhere.