ECU Gone Bad???? HELP!

[Mike Marnik]

OK so every 3rd day or so it all depends on how ### my car wants to be i get cel for coolant temp sensor, air temp sensor, and barometric pressure sensor. It seems to happen more when i do alot of driving where i stop shut the car off to go in a store or something then go drive again then go to another store type of this dunno if that has anything to do with it. then if i let the engine cool off completely like over night it will work fine in the morning. Also when i get these cels my knock sensor goes whack also and read 43 constantly i don't understand its new and work properly at all other times. Also when the cels come on the sensors it comes on for read this Coolant Temp: -25 Air Temp:-121 Barometric Pressure:123. also the tps begins to no longer work it also pegs out at 100%. I have already gone threw the wiring harness to see if there are any bare wires and there are not. Ive disconnected the ecu for probally 30 min + i also took it apart and it didn't apprear to have leaky caps or smell of rotten eggs. I'm really at my witts end on this one only thing i can think of now is a bad ecu. Any other opinions or answers would be appreciated. I am going to try and see if one of my dsm friends will trade me ecus for a few days and see if it keeps doing this to me or if it does it to him to figure it out. please guys i really need help thanks.

 

[steve]

Those sensors share the sensor ground so it's possible you have a loose connection/broken wire or that the ECU has some problems. I've seen both. There are several ways the ECU can fail causeing this sort of problem. You need to have somebody that knows what to look for check your ECU if you can't find anything in the wiring.

Steve

 

[Mike Marnik]

Where exactly is the ground for those sensors at i will check that first and probally make a new ground wire. it is also possible it is loose or was possibly not put back on right as i just pulled the engine and got it put back in. if its not the ground im going to swap ecus for a few days with a friend see if it does it to him or keeps doing it to me thanks for the help.

 

[steve]

It starts at ECU pin 24 and branches out from there but I can't tell you the actual routing in the car. It's a green with black stripe wire that runs to the various sensors.

Steve

 

[Mike Marnik]

Ok well i removed the ecu again today and the sensor ground seems to have a good connection but i did fin ecu pin out #106 which is also a ground to be loose so maybe that is the culprit? i am going to see if it is acting up now that i have secured the ground in better. BTW after sitting over night it did not fix itself this time.

 

[Mike Marnik]

ok well i secured the wire and it is getting a good connection. i also checked all the other wires and made sure they had a good connection. it has to be the ecu all the wires are in good condition. i dont know where to take the ecu to have some one look at it to tell me if its really gone bad or not if any one has any reccomendations. i am going to check one last time but next step is to swap ecus with my friend.

 

[Mike Marnik]

well i figured it out it is the ecu. me and my friend switched them out and it no longer happens with his ecu in and it did the same problems to his car with mine in. thanks for the help.