chriscolor1

Hello all, I have a 01 s4 tip and im having an issue with the epc light. I recently put in a giac x chipped ecu and all is well but randomly when you start it, the epc will come on and stay on. It will run fine but looses a little power and boost(like a light limp mode). If you unhook the batt, it will clear the epc and then its good again for awhile. No cel codes ever come up. Also since Ive installed this ecu, the cruise wont work. I have replaced the brakelight switch. Im just looking for some direction to remedy this and any help would be appreciated.

EuroXS4

The only thing I would recommend checking is the coding of the ecu that you installed into the car.To be honest it sounds like a hardware issue aka ECU not being compatible with the car or something along this lines.Maybe some adaption channels need to be changed.Whats the part number of your original ecu and the one you put in. and out of what car did the ecu come from.auto or manual??Also information about your car and the ecu you put in would be handy.Is it possible that the ecu you put in came out of a manual car??that that case you would need to change the coding in ecu.simple job 5mins if you have a vag com.

chriscolor1

Thanks for the reply. I thought of this compatibility issue but I believe they are compatible. My cars original ecu is a J box and the one I put in is a L box. Idk, I suppose I need to get a vag com cable and learn to use it but I just thought I had something wrong here. My car has this ecu, 710N valves, ECS race N75, new upper o2 sensors, cone air filter, new egt sensors and new torque converter.

twv5004

Psh epc lights are the plague, I've replaced epc, abs all ecus that go with em and I still get the same, some say it's a bank sensor that detects when your cars banking into a turn which cuts partial power doing epc magic, I've been told what this means is your car thinks it's banking so it kills a lil fuel assuming your taking a turn, good luck finding which parts causing it but don't sweat it, ur cars not gona blowup from it

EuroXS4

A sensor cutting fuel off while banking??Sounds like myth to me.Id say get a vag com cable and check what faults your throwing.Also make sure the ecu or cluster doesnt need to be recoded or adaption channels.The ecu you put in your car came from a manual car or automatic??

chriscolor1

The ecu I put in it came out of a 01 s4 automatic. Oddly, this problem seems to be getting better but not fixed. What I mean is that when I first put this ecu in, the epc light was on immediately. Now almost 2 months later, I can go a week sometimes before it will come on. Its my understanding that the epc light is directly related to the drive by wire throttle on these cars. Someone suggested to do a throttle alignment with a vag com. Shouldnt the car cycle the throttle and align itself? Again thanks everyone for helpin a new guy..

Peter Badore

Are you using VAG-COM to scan your S4?

chriscolor1

I dont have a vag com yet. When I get one, ill have to scan it when the epc light comes on and see what I can find out. If it werent for dash lights on VW/Audi's, what would we do with all our free time??

chriscolor1

Ok, got my vag cable. I figured out the epc light problem and my cruise control prob. The ecu that came in the car was an L box(2001.5). The chipped one I put in is a J box(2001). Long story short, I had to recode my instrument panel to the earlier ecu. All good with that. I now need to find egt's for a decent price :/