Driving a 2001 3.8 mustang with an automatic trans. Just had a tune up a month ago, new plugs new wires. Overnight one day i started the car and it was running really rough, shaking the whole car. Immediately upon driving off noticed theres a major lack in power and the engine struggling to push the car. I took it to autozone the same day when the check engine light started blinking. It ran an egr code which it has been for a while. I know i need a new egr valve. But also running a cylinder 3 misfire code and one autozone couldnt check for me. All they could tell me is their scanner read a "u1262" code for communication bus failure. Ive done some searching and cant tie the two together though they both appeared at the same time. I dont know if a bad coil pack could cause the u1262 code but obviously could cause the misfire. Before i change the coil pack i was hoping someone could offer some advice. Ive had the car since febuary bought with 44k original miles. Prsonally know the owner, she drove the car to work and thats it. Its got 66k on it now. Any help would be greatly appreciated. Thanks in advance guys

 

Might want to hunt this down:

TSB Number: 17868 Intermittent loss of power or crank no start - possible pats lamp flashing and diagnostic trouble codes (DTCs) U1147 and/or U1262.

I have also heard of communications problems being caused by the Code scanner telling the PCM there was a comm error. Then the PCM sets a comm failure code. Sort of ironic.

On the other hand you said the MIL was flashing which is considerd a serious malfunction. Normally if it were just an EGR it would be a steady light.

 

Thanks for pointing me inthe right direction, im doing some digging on that tsb.

As far as the code scanner causing the problem i dont see that being possible as the SES light started blinking before i got the car to autozone.

Im %100 sure its not the egr, i know i need one but that shouldnt cause this kind of problem, as far as i know anyway.

 

Did you try and reset the ECM by unplugging the battery for 1/2 hour? Ive had to do that everyonce and a while when mine throws a random code and some times it works to sort things out. Just an idea, its fast and FREE!

Matthew

 

Yeah it was off battery for two days and still same thing as soon as i fire it up. It takes a day or two of driving for the check engine lght to start blinking so i try not to drive it much. Could the coil pack be causing the other code(u1262)?