9BASE3

Again...



Ok here's the deal.



Put the key in the ignition and turn it to the on position.



Attempt to start car. Nothing.



Turn key back to on position and wait.



15-20 seconds and the CEL light will begin to flicker and some sort of relay (Fuel pump I think) will make a machine gun sound in sequence with the light. Machine gun sound will turn to more of a buzz then stop. As will the flickering. CEL is now on steady and the car will fire RIGHT UP.



This is getting WORSE.



It started a few months ago. First it was just a few seconds, then more, then a lot, then nothing... The ECU fried doing whatever the **** it is that it does during this phase (POST test I imagine) of operation.



I replaced the ECU and everything was grand. Turn the key and no funny noise, no waiting and no bullshit. Gradually it came back and now I'm at the point where in a few days I'm certain the ECU will burn again. CAN ANYONE shed some light on this POS??



The garage that replaced the ECU before said there was a communication error in the ECU. Replaced it and all was good. But it's back. I know the ECU is going to go again... But I can't figure out what is causing it. It's VERY random.



There are no recalls that haven't been done, and the dealership said they have never heard of suck a thing. (But of course they havent.. But after a 85 dollar diagnostic they'll be happy to tell me all they know.. **** that.)



I have money for the person that solves this. Fifty bucks. However you need it. MO, Paypal, you name it.



Thanks!

Rob x-7

did you have someone put it on a scanner ?

9BASE3

Yeah. Nothing. The communication error led them to the ECU. Replaced it and codes were clear. Now if I put it on the scanner I'd imagine they'll see whatever crap it was last time. Something is frying the ECU over time.



Could the relay be fucked up and the ECU burning from trying to trip it? It has SOMETHING to do with the fuel system... The las little part I hear is the fuel pump coming on, when normally it is right on with the key...

Rob x-7

maybe there is a jeep forum somewhere and somebody has some

input on it?

turbovr6

where is the relay machine gun sound coming from? under the dash? under the hood?



In that vehicle if you turn the key to the on position, then off three times in a row the CEL light will flash any diagnostic codes. See if there are any codes and post them here. It's just like a mazda withe the long flash short flash sequence to get the 2 digit code

Rob x-7

anyhow, im going to lean towards a short someplace, maybe a exposed

wire someplace, i dont know, dont you have a GOOD mechanic you

can take it to?

turbovr6

you hear the fuel pump come on after the machine gun noise goes away? allthough there is a fuel pump relay, Chrysler uses what is known as an ASD "auto shut down" relay. If that goes bad, no fuel, no spark, no crank........

j9fd3s

seems like its not getting power/ground?

TheCamel

Sounds to me like there is a problem with resistance in the circut, I would check the connections for the relay and surrounding grounds. The ECU frying may be due to it attempting to find another ground internally, which as you found out, is a bad thing. Is the gas gauge acting erratically or anything? if it is, the ground problem may be by the fuel pump. The CEL light is storing a code, that is why it is blinking. The diagnostic system the local shop used may not have been able to communicate due to their software, Lots of smaller shops buy an accross the board unit like a Snap-On MT2500 which requires new cartridges to be bought each year at close to $1200, If they do not have an updated chrysler cartridge they may not be able to communicate. Not saying they screwed you, not sure if they were able to communicate with it after changin it or not, you don't say in your post. But as long as it is doing it now, I would have it checked out. Chrysler is famous for bad grounds is why I mention it.



Sean

9BASE3

It seems to come from under the hood/dash. But the last part of it, where the sound changes, it comes from the back by the tank. That's why I'm thinking fuel relay or something. Strange that with the new ECU it went away, then gradually found it's way back..