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Registered
'02 ETC 34,000 miles 2002 F55 STS 83,000 miles, 2016 Challenger SRT 392, 6 Sp.
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264 Posts
Discussion Starter #1
So my SES light came on today. As soon as I got home, I pulled codes and only got these history codes, nothing current.
- IPC U1016- loss of communication with PCM
- B1327 - Voltage below 9.0
-U1000 - Class 2 communication malfunction
-TTM U1016 - loss of comm???
and
-P0300 - misfire
If these are all history codes, what tripped my SES??

Are there other things that trip the SES, that don't throw codes?

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Oh, and what types of problems typically cause a mis-fire. By the way, talking about the 2002 STS.
 

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Registered
'98 STS (RIP @ 206,xxx miles)
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4,854 Posts
Re: Ses light on, no current codes

....B1327 - Voltage below 9.0
One more time!

A B1327 code renders any and all other codes/messages "unreliable". Repair the issue that caused the B1327, clear all codes, and start with a clean slate.
 

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Super Moderator
2010 DTS
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87,430 Posts
Re: Ses light on, no current codes

P (PCM) codes are the only codes that trip the SES light. That said, low voltage seems to cause false codes and it might be possible that the B1327 caused the P0300 which tripped the light. Like Jim said, you gotta take care of that first.
 

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Registered
'02 ETC 34,000 miles 2002 F55 STS 83,000 miles, 2016 Challenger SRT 392, 6 Sp.
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264 Posts
Discussion Starter #4
Re: Ses light on, no current codes

So, my battery or alternator may be bad?
 

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Super Moderator
2010 DTS
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87,430 Posts
Re: Ses light on, no current codes

More likely the battery. What's your voltage at KOEO (key on engine off)? Also while idling.
 

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Registered
'02 ETC 34,000 miles 2002 F55 STS 83,000 miles, 2016 Challenger SRT 392, 6 Sp.
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264 Posts
Discussion Starter #6
Regarding my 2002 STS - 55,000 MILES:

I've got 12.1 at KOEO, and 15.1 at idle....... sounds OK to me.

I took her on a 600 mile round trip over Christmas, it was the first time I'd really had a chance to ring her out.....ran great.....what a machine!
I let her sit for a couple days, and much to my chagrin, when I started it up today it ran a little rough, and again I got the P0300 mis-fire code. It smooths out after a minute or so of running.

What is most likely the cause of the mis-fire?
It almost seems like there is a fouled plug, and then whatever is fouling it burns off after a minute or so and then it runs fine.
What else could cause this condition? .....No coolant issues evident, not using any coolant or an excessive amount of oil as far as I can tell.
Also, no other codes besides P0300.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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20,104 Posts
Regarding my 2002 STS - 55,000 MILES:

I've got 12.1 at KOEO, and 15.1 at idle....... sounds OK to me.

I took her on a 600 mile round trip over Christmas, it was the first time I'd really had a chance to ring her out.....ran great.....what a machine!
I let her sit for a couple days, and much to my chagrin, when I started it up today it ran a little rough, and again I got the P0300 mis-fire code. It smooths out after a minute or so of running.

What is most likely the cause of the mis-fire?
It almost seems like there is a fouled plug, and then whatever is fouling it burns off after a minute or so and then it runs fine.
What else could cause this condition? .....No coolant issues evident, not using any coolant or an excessive amount of oil as far as I can tell.
Also, no other codes besides P0300.
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what was your gas mileage over your 600 mile trip -

check the Fuel Pressure Regulator -
pull the vacuum hose - it should be dry - no sign of gasoline -

check the fuel pressure at the rail - it should be around 45 at idle -

you could have a fuel injector that is sticking -
when you shut the engine off - the fuel could be flowing through the leaky injector
until the fuel pressure is bled off -

you can "rent" a fuel pressure kit for free from AutoZone -
or other large auto parts stores -

connect it - run the motor for a few minutes - then shut it off -
observe how long the fuel pressure is maintained -

the P0300 code is a generic misfire code -
and it is a code our on-board reader falls short on -
in that it will NOT tell us WHICH cylinder/cylinders is/are misfiring -
that information IS stored in memory - it is just NOT displayed -

AutoZone - or other big auto parts stores will check your codes for free -
P0301 is a misfire in cylinder #1 - P0302 is cylinder #2 - P0303 is #3 - etc -

find out whic cylinder is misfiring - it makes diagnosis much easier -

the odd cylinders are in the rear - even in the front -

1--3--5--7

2--4--6--8
\/
front of car
 

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Super Moderator
2010 DTS
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87,430 Posts
I let her sit for a couple days, and much to my chagrin, when I started it up today it ran a little rough, and again I got the P0300 mis-fire code. It smooths out after a minute or so of running.

What is most likely the cause of the mis-fire?
When was the TB last cleaned? I'd start there.
 
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