mustangmanjeff Posted September 15, 2013 Report Share Posted September 15, 2013 (edited) 95 mustang check engine light came on bucking in 2nd gear code 51 / 511.Like title states My check engine light randomly came on, and I notiched the car is bucking accelerating not smooth in 1st and 2nd gear kind of lag then it goes and kind of bucks. I went to autozone to check with obd1 scanner what a pain, the number I belive Im getting is 51 or 511, which is saying something to do with the ecm computer and other is for temp sensor or t start etc. Not sure that would cause that problem. But I know last year or year before I think i had check engine light as well code 511 and it was nothing you reset it? Cant remember. I know the t stat and temp sensors are new. And a new coil just replaced just about everything I was thinking it was bad gas or bad 02 sensor or a bad coil pack. what code it be?2 codes I got?[TABLE=width: 566][TR][TD=width: 28, align: center]51[/TD][TD=width: 63, align: center][/TD][TD=width: 453, align: center]Engine Coolant Temperature (ECT) sensor signal is/was too high – ECT[/TD][/TR][/TABLE]and[TABLE=width: 87%, align: center][TR][TD]511[/TD][TD](O)[/TD][TD]No power to PCM pin 1 or bad PCM (processor)[/TD][/TR][/TABLE] Edited September 15, 2013 by mustangmanjeff Link to comment Share on other sites More sharing options...
mustangmanjeff Posted September 16, 2013 Author Report Share Posted September 16, 2013 anybody? lol Link to comment Share on other sites More sharing options...
Det_Riot Posted September 16, 2013 Report Share Posted September 16, 2013 What are the mods you have? On my phone so if it says in your SIG I apologize. Have you changed anything recently? Different gas station? Link to comment Share on other sites More sharing options...
64bit_Tuning Posted September 16, 2013 Report Share Posted September 16, 2013 make sure the computer does not have an aftermarket chip plugged into the J3 port. code 511 is pretty normal if the car has ever been tuned. Link to comment Share on other sites More sharing options...
mustangmanjeff Posted September 16, 2013 Author Report Share Posted September 16, 2013 What are the mods you have? On my phone so if it says in your SIG I apologize. Have you changed anything recently? Different gas station?My mods are the same it just randomly happened as i drove it last night, It was fine saturday, then sunday I started it started fine no check engine light and after driving couple miles the check engine light came on, i shut the car off it went off didnt come back on then it came back on later that day and stays on wouldnt come off, then I notiched it bucking and acting laggy in 1st and 2nd gear around 2,000 -3,000 rpms, i would floor it it kind of hesitated and bucked and then would go then kind of buck again. Im thinking bad gas, because now its on empty it isnt as bad, I unplugged the battery and knock on wood the light went off hasnt come back on I hope im going to put new gas now im on empty, Im hopeing it was just that.- - - Updated - - -make sure the computer does not have an aftermarket chip plugged into the J3 port. code 511 is pretty normal if the car has ever been tuned.Yeah i saw this is common for chipped cars, but its had a sct chip in it for years now, I had similar problem last year but I got it retuned it went away and has been good for over a year. I havent changed anything since then so it randomly came on is weird. hopeing thats it,I dont feel like getting it tuned again right now. Link to comment Share on other sites More sharing options...
Sleeperstang1994 Posted September 17, 2013 Report Share Posted September 17, 2013 i would start with the easy things instead of speculation. Ohm out your ECT sensor to make sure its not open. the pcm will see an open sensor as infinite,or high, resistance. it might just be a bad sensor. As for the PCM code. verify you have 12 volts on pin 1. if there is no voltage grab a wiring diagram and check for bad fuses. it could be relatively simple. you just need a place to start Link to comment Share on other sites More sharing options...
Str8racn Posted September 17, 2013 Report Share Posted September 17, 2013 Mine did this a couple months ago. Drove me crazy trying to figure it out. Turns out all I needed to do was clean the MAF with the MAF cleaner which leaves no residue. Light automatically turned off and stopped bucking. Mine started bucking worse and worse the more I drove it. May give that a try. Link to comment Share on other sites More sharing options...
mustangmanjeff Posted September 17, 2013 Author Report Share Posted September 17, 2013 Thanks guys! Link to comment Share on other sites More sharing options...
GearGambler Posted September 18, 2013 Report Share Posted September 18, 2013 let us know when you figure out the issue! please follow up Link to comment Share on other sites More sharing options...
Det_Riot Posted September 18, 2013 Report Share Posted September 18, 2013 Any updates Jeff? Link to comment Share on other sites More sharing options...
mustangmanjeff Posted September 18, 2013 Author Report Share Posted September 18, 2013 let us know when you figure out the issue! please follow up I will let you know when I drive it next I dont daily driver the car so I only drive it on the weekends.- - - Updated - - -Any updates Jeff?I will let your know when I drive it again , knocking on wood crossing my fingers the light doesnt come back on after I reset the battery. Link to comment Share on other sites More sharing options...
