Check Engine Light

[SamPap]

Today on my way home the check engine ligh came on. The truck seems to be running fine. The oil level is good. The codes that came up are as follows... .....



67 56

A4 53

AC 10

00 00



How do I decifer these?



Oh, and by the way the truck is all stock with the exception of the muffler delete. I just removed the muffler 2 days ago but left the cat in place. 2200 miles.



What should I look for?

 

[artie]

The latest error is the "AC" as it has only seen 10 ign cycles since error happened. The "AC" error in 04 shop manual is "ABS messages not received".

 

[Matt400]

Originally posted by spap

The codes that came up are as follows... .....



67 56

A4 53

AC 10

00 00



How do I decifer these?

Those are dash board codes and I am not sure but I don't believe they will set a check engine lamp.



67= All door lock output circuit shorted to ground or power, the second number- (56) is the number of times the key has been turned on since the event.



Don't know what the A4 is

AC= ABS Message not received

00 = done testing



You may be a candidate for a dashboard re-flash, I took mine in on Thur for the reflash and my whole cluster blacked out when they tried, now they have to replace it.

 

[SamPap]

Thanks for your input guys... ... ... The engine light is now off and I will be monitoring it very closely.



Do you think that removing the muffler triggered the light to come on? Or is it coincidental?

 

[SamPap]

Also,



I checked for codes a second time and this is the result...



67 59



A4 56



AC 13



00 00



After checking these codes the light did not come on again.

\

I was under the assumption that to turn off a light the truck must be diagnosed and then serviced/reset at a shop.



Is it normal to trip a check engine light and then it corrects itself somehow and goes away?



Thanks Again, Sam

 

[Matt400]

Originally posted by spap

I was under the assumption that to turn off a light the truck must be diagnosed and then serviced/reset at a shop.



Is it normal to trip a check engine light and then it corrects itself somehow and goes away?



Thanks Again, Sam

I don't think your muffler had anything to do with it.

When the engine is running the software is constantly running tests on various circuits and if something doesn't pass a test the a code is set and the lamp goes on. Those codes are stored in the ECM and not the dashboard. When a specific test that had failed later passes as the tests are re-run it can command the lamp out.



I wouldn't worry about it for now but if your by a Dealer you can have then check the ECM for any stored trouble under your warranty.



Disconnecting both neg. battery cables will also clear a check engine lamp unless its a hard fault that simply causes it to come back on right away.

 

[Blakers]

Originally posted by Matt400

Disconnecting both neg. battery cables will also clear a check engine lamp unless its a hard fault that simply causes it to come back on right away.

There's supposed to be a way to clear codes by just turning the key on and off in a certain pattern. My cousin's dealer told him how to do it. Ask your dealer.

 

[thames1948]

How does it sound without the muffler and ring? If I do mine, I too will leave the cat on.

 

[Matt400]

Originally posted by Blakers

There's supposed to be a way to clear codes by just turning the key on and off in a certain pattern.

That would sure be more easy for the DIYer, I never heard of that procedure. On my own stuff I use a scan tool.

 

[Blakers]

Originally posted by Matt400

That would sure be more easy for the DIYer, I never heard of that procedure. On my own stuff I use a scan tool.

Let me see if I can find the details.

 

[rbattelle]

spap,



You're posting the dashboard codes, which will not illuminate the check engine light. You need to post the ECM codes to find the real problem. Cycle the key 5 times (I think) and it will spit out the trouble codes in the ECM. Post them here and we'll tell you what your problem is.

 

[LHebert]

Cycle the engine 6 times and it will go away.

 

[SamPap]

Thanks to all for the help. I cycled the key 5 times and the codes that were dsiplayed were... ...



P 0480



P 0243



And also, I cycled the key six times and the codes did not clear.



The truck sounds really good w/o the muff and silencer ring. However, I probably will be getting a flo thru muffler installed in the near future once the novelty wears off and the drone becomes to annoying.



ANy reccomendations on a good flo thru muff? I was leaning towards a donaldson.

 

[Matt400]

Originally posted by spap

P 0480, P 0243

P0480= trouble detected with the fan control ckt. (engine vistronic fan) not your heater fan.



P0243= trouble detected with the turbo waste gate

ANy reccomendations on a good flo thru muff? I was leaning towards a donaldson.

I think the Nelson #86514 might be a good muffler up to 375hp. It has a 4" inlet and 5" outlet so would bolt right up but you would need to find a 5" tail pipe.

I haven't changed mine yet but may go with that one. I still have to find out how long it is for fit. I do know its 9" in diameter.

 

[Matt400]

BTW Those are generic OBDII code meanings that I had to find elsewhere. Pretty weird I couldn't find a code chart in the factory manual. If anyone has the factory manual and has found a DTC Chart please post where its at.

 

[rbattelle]

P0480: Fan Clutch.

"The PWM signal to the fan clutch doesn't match the PWM signal from the fan clutch".

(PWM = Pulse Width Modulation)



P0243: Hmmmm... this code isn't in the book.



[In case you meant P0234, that one is "Turbo Boost Limit Exceeded". ']



Sounds to me like either your fan clutch wiring harness is broken (wasn't this a problem with early '03s?), or the clutch itself is bad.

 

[Blakers]

Originally posted by spap

ANy reccomendations on a good flo thru muff? I was leaning towards a donaldson.

I bought one from a Mack dealer for $75. 4" in and out and straight through. Only about 20" long. I have not put it on yet.

 

[dmccullock]

Thats interesting that your truck shows those codes because so does mine. After starting my truck the check engine light came on. Checked the codes they were P0243 P0480 and more recently P0524. I have not taken it to the dealer yet . If you do let me know what they say.

 

[Grieke]

Hi Matt400,

What kind of a scan tool are you using, and would you buy the same one again?

I am in the market for one.

Thanks.

 

[Matt400]

I use a Snap-On MTG2500 and keep it updated.

I need it because I work on many different makes. If all I did was one make I would use the OEM scan tool.



If it was for personal use I would look at software for a PDA and use manufacture enhanced software.