"limit exceed" a common enough code when engine is modded nothing to worry about just clear it

 

I am going to go to autozone after work, and I don't have a N75 because i herd they don't work on B6 cars, and people that do try to use them do go into limp mode often

 

well good luck mate, remember this though (if you upgrade the engine and don't do it right you will put a load on the computer that wasn't made for the software) many faults are spurious because of mods taking standard items like the o2 sensor + many others to their limit so its an unknown gray area which develops when people do mods and inform others of their results "then we all learn"

 

Limp mode is technicaly a safe mode that the tranny goes into. What most people confuse limp mode with is closed loop mode-where it cuts your boost/timing/fuel back to stockish levels. It usually goes away by simply restarting the engine. It happens sometimes with a chip and n75 race valve when you are gettin on it real hard -the ecu detects intermitent overboosting which is common in high end rpm "FLOORIN IT" situations.

 

I was going to say that but didn't want to get too technical

 

It happens to me sometimes, and this is the code I get from it:

Address 01 -------------------------------------------------------
Controller: 4B0 906 018 Q
Component: 1.8L R4/5VT G 0005
Coding: 07051
Shop #: WSC 06335
1 Fault Found:
17964 - Charge Pressure Control: Negative Deviation
P1556 - 35-10 - - - Intermittent
Readiness: 0000 0000

 

see your getting technical but at least I under stand it, this happened with my rover 827 sterling with programed fuel injection, I boosted to 300hp simply by reprogramming the chip in the ECU lovely sound till it blew the engine into a million bits which I think added value to a rover

 

Yeah limp mode is when you lose voltage to one or more components on the transmission. there is also a default mode and that is a loss of an input to the transmission. Most of that stuff has to do with an auto trans though. In an auto trans limp mode would only give you one gear where as default would just make it shift hard

 

I dont know about that "closed loop" mode. Closed loop is when the computer starts looking at the o2 sensor for an input. open loop is before the 02 heats up so the ecu looks at other things to get its calculations

 

Same idea, the ecu disregards certain aspects of programing and looks elsewhere to make its calculations... There may be a more technical word for it pertaining to whats happening, but closed loop is what I have heard the "experts" call it.