car keeps going into limp mode i dont know why need some help i replaced the main harness like a week ago because my old one got shorted out the first night i drove the car after the new harness it drove fine with no problems then ever since its been going into limp mode if you guys can think of anything that would do it please lmk or if any wires that could be unplugged that would make it do it.... also my turn signals no longer work

 

First step is to check the ECU error codes. Check the faq or search to learn how. Something has to throw the ECU into limp mode, the error codes will tell you what. Given this is an S5, the MOP may be a good bet.

 

http://www.banzai-racing.com/FD&S5_error_codes.htm

Turn signals: Check the Turn fuse and Hazard fuse in the interior fuse box.

 

yea probably a good chance its blown ill check here in a min and doesnt autozone do engine checks for free?

 

Yes they do.

 

alright ill probably run up there ill let you guy know if i get it figured out

 

I'm just guessing, but that free scan may only apply if your car is OBD2 or later. FCs were not OBD2.

 

hehheh!..Rx7's are more like OBI WAN KANOBI than OBD2!..seriously!..you gotta use "The Force" to diagnose these cars!

 

I was just answering the guys question

Really, if he would look at what the people posted for him he would have figured it out by now instead of wasting time at autozone getting told its for OBD2 only

 

I would agree. If he can replace a harness, he can check for codes. Like I said, I was just guessing that it would be for OBD2 or later cars, as OBD2 is when the system became more standardized, if I recall correctly.

 

Your OMP might have stopped working.

 

S5s usually go into limp because the omp took a ****, they also have the tendency of taking out the ecu.

 

ok first off dont knock on the thread never went to autozone i wouldnt let those dumbasses ever touch my car just getting some opinions.. anyways i was messing with the car today and i pulled the airfilter to just see if the car was leaning out for whatever reason and when i covered up about 1/3 to 1/2 of the maf the car revved fine kinda like its getting to much air...i dont think the omp would have anything to do this do you guys?

 

also can someone send me a link on how to check the codes on an s5

 

A simple test to tell you if the cat has a vacuum leak after the tb fully cover the tb with your hands if it still runs then you got a vac leak after the tb.

 

Post #3 has a link on how to check codes on an S5.

 

I meant to say if you think the car has a vacuum leak.

 

thanks guys it ended up being the OMP i replaced with a turbo 2 one off my buddys motor runs great now thanks for all the help