Help with DTC code

[huangzl99]

I got a strange problem. A week ago, my lincoln ls 2006 V8 got an engine light on, and the code was P0355. I borrowed a scanner and tried to clear the code since I like to see if it comes back. The problem is when I put the ignition to on (engine not started), and press the clear button, the car suddenly went wild and cannot start any more. it looks like the anti-theft system is triggered...

I have dealer looked into the car. They replaced my battery and uses their programmer (a dealer laptop) to clear all the DTC code. These codes indicate the PCM cannot communicate with some subsystem, like ABS and track control. These maybe due to the battery.


After clearing the codes, the car returns normal and can drive without a problem. but when reconnect the programmer to the car and read the DTC code, they all come back! it looks like the code cannot be erased or it was erased but come back. The fault lights in dashboard are not lit - I assume the self check on start up passes. But why these codes still there? Can I say, as long as the dashboard does not tell any problem, it should be good and these code are just previous codes not erased properly? any thoughts?


Thanks a ton!

 

[joegr]

I suspect that the persistent code issue is that your specific "programmer" has stored those codes.
The P0355 means that you need to change all of your spark plugs and COPs (coils) now. You probably won't. You'll be back with more weird problems. Eventually, you'll have ETC failsafe happen a few times, and you may wind up having to also replace your expensive catalytic converters.

 

[huangzl99]

I suspect that the persistent code issue is that your specific "programmer" has stored those codes.
The P0355 means that you need to change all of your spark plugs and COPs (coils) now. You probably won't. You'll be back with more weird problems. Eventually, you'll have ETC failsafe happen a few times, and you may wind up having to also replace your expensive catalytic converters.

The P0355 indicates it is ignition coil #5, why I need to change all coils? Thanks!

 

[1LoudLS]

here we go again...



quick and dirty: most of the time when you are having a coil problem it does not throw a code. most of the time, when one coil is failing (especially that badly) the probability is great that you have other failing coils as well.

so you can keep buying one coil at a time and always be chasing a car that runs sh!tty and by the time you finally get to replacing them all and fixing the problem, you would have probably killed your catalytic converters which is going to cost you a lot more than a set of coils and plugs would have from the beginning.


better yet, try searching just a little... if you would have put minimal effort into looking, you would have ran into many threads that would have explained everything you've been asking.

 

[LS4me]

Hmmmmmmmm........