Please help!

After leaving a restaurant Saturday evening, driving my '08 r55 that was still cold, I pulled on the highway with mild acceleration only to have the car go into "limp mode" (car will not go more than 30 MPH).

DTC (Diagnostic Trouble Codes) are U114B and U115B "lost communication with engine control torque 1". U115b is same with "torque 3".

I researched everywhere, called mini only to hold for 20 min. and have them tell me the there is "no one available at the moment", anyone have any ideas what that means and what repair it suggests?

I have cleared the code and plan to test drive the car, but I always error on the side of caution; something caused the fault and I hate to drive it without knowing what the trouble was.

Thanks for your help!

 

I've compression tested, all between 150 and 160, swapped the plugs, then swapped the coils, there is no smell from the exhaust (hope that's telling about the catalytic converter), I'm about to swap out the injectors.

Any other thoughts?

Thanks for any help available!

 

Hey, did you ever find out the cause? I'm getting similar issues. My car doesn't go into limp mode, but I experience low power frequently.
Thanks!

 

Although this is an old thread, I thought I could add a bit of info on "U" codes. U codes, unlike P codes, can be VERY misleading since sometimes only an engineer at the factory really knows the logic trail of why one is set or being stored. They are generally referred to as Communication Codes, and are often an off shoot of a wiring or sensor issue that causes one system to go into failure mode, while putting other systems on the same CAN BUS into a partial fault mode since that first system went down, even if it's an intermittent thing.
This is one of those times where having Factory Diagnostic software can edge out aftermarket software by a long mile since the factory people who designed the systems can ask for a session file on the vehicle and read all sorts of info hidden in the background that you aren't even aware was being stored to help determine the Chicken or the Egg path to fixing the vehicle with multiple U codes being set, and not much else being shown in the way of faults.

 

Hi Red,

Thanks for the response. I sort of expected as much. If you're interested in more info, I have an intake build thread at:

https://www.northamericanmotoring.co...ml#post4066817

If you're able to get thru that, it might provide more insight. Retrospectively, before doing any mods to my car, the car always felt under powered. Sometimes, it would be peppy, but mostly, it didn't feel like a light-weight turbo car. Before installing the mods, I didn't run a scanner to see if I had any hidden codes. I'm also wondering if the P2882 appears with the U codes on occasion.

The worst part is that I've been so busy this past week, that I haven't been able to hook up a scanner and see what's happening now. During my daily drive to/from work (~14 miles), the car is typically a bit peppier (but by no means a speed demon) about 1/3 of the time. I'd guess when it's not 100% warmed up - I'm acutely aware of this stuff now, but the reality is the butt dyno is not very accurate. Please feel free to respond here or in my other thread.

It'd be great to get some more insight from you.