Hello,

I have a 2003 thats been having a weird issue with CEL and codes lately. The car keeps throwing codes for: Knock sensor, Vehicle speed, Injector circuit, fuel pump relay, barometer and im sure others im forgetting right now. Each the CEL comes on i check the DTC's with evoscan its 1 or 2 of the above codes. I than erase the codes and they come back 5-10miles later. The car runs fine though, which has me a bit confused. I figure if there really was a problem with the fuel pump relay the car wouldnt be running, or at least running poorly.

This all started after putting solid motor mounts in my car. Is it possible these sensors all share the same plug or ground that might have somehow come undone? Ive visually checked and everything looks ok. Ill be getting under the car more this weekend but dont really know what im loking for at this point.

Any help or a point in the right direction would be appreciated.

 

It sounds like you are on the right path.

 

I spent a bit of time under the car this weekend. I checked every plug and ground under the hood i could find. Nothing seems out of order. The problem has gotten worse. the car now throws a few codes each time it starts up. If i clear the codes and start the car it doesnt seem to throw the codes untill the next time the car is started. It seems like it just picks a few random codes to report each time.

Im really stumped here. Ive tried a couple different rom versions on the car with no success. Could the ecm be bad? I really am trying not to bring it to a shop and pay a lot of money for exploratory services.

Any help would be greatly appreciated!

 

Check voltage comming off from your alternator and to your battery. It is possible that it has **** out and messing with your ecm. ( have had tseen this a few times with other vehicles.)
Are there any other dash lights on becides the CEl?

 

I havent checked the battery voltage yet but i will tomorrow. Thanks for the idea

-Matt

 

I checked the voltage off the battery with the car running and it was a solid 14.25v. Checked it with the car off and it was about 12.8.

Ive noticed 2 things the past couple days. I only work a couple miles from where i live so most of my trips after clearing codes are 5 miles or less. The CEL doesnt usually come on as im driving but seems to come back pretty regularly as im cranking the car over to drive the next time. I than clear the codes and start the process over

Also, once in a while i get an EGR error. I have EGR disabled through the Tephra v7 periph bits. I shouldnt be getting this code right? Could this mean there is a problem with either the rom or the ecm itself?

 

I would try to get ahold of a buddys ecu and swap it to see if that is the problem. OR buy a new one and if it is not it you can sell it rite back.

 

Thanks, I think that's what im going to do next. Im hoping to find someone local that I could borrow an extra one from but I think ill end up buying one. At this point I just want to know what the problem is. Im starting to see cel's in my sleep lol

 

Did you fix the problem? I´m having a similar situation with my EvoV, I get vehicle speed sensor, injector circuit, fuel pump relay, and occasionaly barometric pressure sensor; the first 3 are steadily showing though. The car runs fine when the cels are not lit, but once they lit it misbehaves a little.

Is there maybe a common ground or wire for these sensors that could be loose or shorted?

Cheers,

Ricardo

 

I may have fixed the problem, or at least gotten it under control. I bought another ecu from a vendor on here, tried it and got the same CEL within a few miles. So it wasnt an ecu issue.

A few days later i went to the bank after work and came out to start my car to leave. Put the key in, turned the ignition and the car just went click and everything went dead. My battery terminal had loosened up a bit somehow and wasnt making contact. I noticed the back of the ground terminal had a few cracks in it so i replaced the terminal. At the same time i replaced the positive terminal and ditched that fuse that was on the terminal. I also replaced the main battery ground with a more solid 8guage wire.

Since doing those changes i havent had a problem with the CEL turning on. I havent checked for any stored codes lately but will later tonight. It hasnt kicked on the CEL in about 300 miles and the car has been running good.

Hope that helps. Ill post back when i check for codes later.

-Matt

*Just checked for stored codes and got nothing! Im thinking it all must have been a charging issue. Im not sure what that metal fuse on the positive terminal was for but it looked like it was fine.

 

Supprised it didn't get caught when I asked you to check the alternater and terminals. God to here it was a easy fix.

 

Yeah, i dont know how i missed the crapped out terminal when checking before. Doesnt look like that was the issue though. I was screwing around with the car last night and loaded a rom onto it i had been working on for a while. Within a few minutes of driving the CEL turned back on. Checked it with evoscan and it was the same old codes. The rom i had been driving around with and had tried on both ecu's was the oldest rom i had, and had no issues with it the last couple weeks. This makes me think the rom is the issue. I had previously tried a few different roms but with no success.

After switching back to the oldest rom im noticing im still getting the same codes being thrown in evoscan but no CEL this time. Ive reset the ecu and cleared the codes but they come right back again. I had been tuning and making changes to this original rom for months and maybe something got corrupted along the way. I may not have gone far enough back in time to select a good rom. Ill keep driving the car and see if the codes go away on their own.

Ugg, I love my evo....

 

Are you VTA on your BOV? When not recirculated your car will run like poop and throw random codes if your still on MAF setup.

 

I'm wondering if it had anything to do with resetting the computer. Because you did unplug the computer for a while. How long have you driven it since then? Also, did you run sea foam or anything? That'll make it throw codes.

 

I run a recirculated turbosmart BOV. Ive checked for boost leaks and everything seems in order.

I did pull of the neg terminal the other night after changing roms again and going back to the original rom. It hasnt thrown the CEL it about 3 days and 60 miles so it think its good for now. There must be something corrupted in the roms i was working with to trigger the codes but doesnt immediately go away after a rom change or even a reset.

This weekend im going to start moving my tuned tables over to the stockish rom 1-by-1 and see if i can pinpoint data what was causing the issue.