So, the situation is that my Sebring is not starting. Fuel pump not working. It is not working because the fuel pump relay is not working. Today was troubleshooting to this moment. Forgot to mention - security system also was checked as it might disconnect FP with relay. everything is OK there. It seems that ECU is not controlling the FP relay. Checked the cable from relay to ECU - good. On relay coil power pins I have +12V (the battery voltage), but very weak current - it is not enough even to turn on the relay. Checked with lamp, also not burning, and the voltage goes to zero when connected and back to battery voltage when disconnected. So, as the cable to ECU pin 21 is good I suspect that its ECU fault. Now simple logic - why do I have that weak voltage on relay coil pins... As the relay is controlled by microprocessor via transistor (it all should be in ECU) one of possible explanations could be that transistor is burned so emitter - collector junction is damaged. And the voltage I see is control voltage from the base of transistor, so it is voltage by which microprocessor controls the transistor.

So, am I right ? If not - other ideas are very welcome.

Will try to take out the ECU (its behind the gloves compartment) and the next question - is it filled with some compound or will the circuit board will come out of the casing and might be tested on the table?

Looks like this:

 

It shouldn't require much current to activate the relay. That's the whole idea of a relay, a small amount of current activates the coil allowing a larger amount of current to pass to the device that is controlled, in this case, the fuel pump. Are you certain that the relay itself is good?

If you are positive that your ECU is the source of the problem, the best solution is to replace it with a re-built unit. Unless you know what you are doing, I wouldn't recommend fooling around inside the engine computer. There are services on the internet that specialize in engine computers. You give them your VIN and mileage, they send you a programmed computer with a postage paid return box so you can ship back your old computer to them. I do not know if they will ship to Lithuania, but I did that with my Sebring and was very pleased with the service and results.

 

Thanks for answer dcotter0579, I know about relays... It should be around 100 mA for standard relay and the MCU sink might be giving about 20 mA so it cant turn on the relay. Could you tell what was the repaired unit price ?

I am suspecting the ECU and came to that by checking everything, but you know, if I made a mistake somewhere... because of that I wrote a detailed description and maybe you guys will see what I didnt...

 

It was over four years ago, but as I remember it, I paid about $200 or $225 which included two-way shipping. I think I found the place on eBay, but there are other services that are competitive.

Here's one. I can't vouch for it, but they are easy to find:

All Computer Resources Dodge Jeep Chrysler Ford GM OEM Engine Computer Auto Computer Dodge PCM Chrysler PCM Jeep PCM Store

 

200 is cheap comparing to ECUs that I found... Cool But I am grateful for your help so will take out (if possible without taking off the front panel) the ECU and try to repair it and give detailed description.

IS it common to Chrysler ECU to have this type of malfunction ? Lets say if the FP relay coil is shortcircuited and the controlling transistor get burned..? Maybe someone will know. Because it might be just a bad contact in ECU pin and all the problems because of that.

 

I can't say that this is a common problem. My ECU issue had nothing to do with the fuel pump and I haven't heard of it elsewhere. You might want to check on Mitsubishi or Dodge forums about your coupe.

 

So, some updates Took out the ECU. Wasn't very hard, I will write the story as I finish, now I am writing because I need the ECU schematics... Can someone share it? Or what transistor is at place Q30 ? SMD, marking:
V0
1H
SOT89 package. PCB has marking JE331B37204A.

 

Ok, I see that noone knows what transistor is in that place. Maybe someone could get the burned or damaged board ? I would take the transistor out and check if it is OK - just replace mine.

 

If you are positive that your ECU is the source of the problem, the best solution is to replace it with a re-built unit. Unless you know what you are doing, I wouldn't recommend fooling around inside the engine computer. There are services on the internet that specialize in engine computers, its nice sharing..!!!

 

Well... I have a masters degree in electronics so... I think I know what I am doing... Just now very busy at work so don't have time to finish this. But after I finish there will be a detailed report