[txmike]

started my 07 Classic LBZ this morning and the check engine light came on. It is setting code P0403 which is EGR malfunction. ????

i had to let the truck idle last night for about 2 hours, could this have caused it? Drove home about 30 miles afterward and no problem. truck has 9,000 miles on it. I have to drive it on a 700 mile road trip on Monday and won't be able to get it in to dealer until end of week. I know it is probably minor but will it affect my fuel mileage?

Thanks for advice.

Mike

 

[txmike]

WTF? all the knowledge and experience out here and no replies!!!???

 

[TYREBOYZ_DEMAXIN]

sorry about this.my LBZ did the same only after i did a exhaust but when i installed my PPE standard tuner it disabled the EGR..letting it idle for a extended time will build up soot and it can throw codes so thats probalily the cause..

 

[John-Boy 331]

block it fingure it love it even more

 

[TYREBOYZ_DEMAXIN]

question did you do any power adders or exhaust?

 

[DuramaxGuy]

Texas Mike -
Code 403 is for the egr solenoid valve... do you have any aftermarket changes to your engine? The extended idle could have something to do with it, but shouldn't. If your dash light is still on, it is proabably still an active code and you should have your egr valve checked. When you shut down your engine, do you hear the egr valve do some movement for about 10 seconds. If so, your valve is probably okay. It is still working.

 

[rick606]

My 06 has done the same thing twice and I have taken it in to the dealer and the clear the code and the light comes back on within a 12 hours. The only fix that they have come up with is to replace the EGR valve. The first time was at around 10-12K miles and the second time was about 25K miles. I did not notice any significant change to my fuel mileage this last time (I had to drive about 5 days before I could get it in to the dealer). The big question is, will this continue to happen every 12k or so miles?

 

[dmax500]

it ain't rocket sience

Dont worry this is a common prob. if you dont have any aftermarket exhaust on your truck i.e. strait pipe. ask your dealer if your vehicle applies to the bullitin to reprogram your pcm with an updated calibration for this issue. also be sure to remove any downloads from a flash programer because you wont have it after they program the pcm.

 

[txmike]

thanks guys. my truck is (so far) all stock. I had a 2005 before this one, with Edge/Attitude and Banks cat-back. The 2007 seems to run a lot better than the 05 did stock. so far i just haven't seen the need to change anything. I will probably eventually do a cat-back to keep down the EGT's. Made a 200 degree difference in that 05.

this truck has 12K miles so I am right in line with other guys having this problem. Could part of it be that I have not been exclusively running ULSD? I have a scanner and I think I am gonna reset the code and see if it stays off before I take it in to dealer.

 

[05_LLY]

A p0403 would indicate a problem with the valve its self. clear it and if it comes backif it dose i would go see the dealer, you egr valve is probally bad!

 

[Dmaximus]

Hey Guys,

I want to put my two sense in also. I have an 06 that is throwing the same code. I done a lot of checking around, because my truck is out of warranty, and the egr valve is not defective. Basically the valve is not sensing the correct position, thus throwing the code. Go with what Dmax500 said and take it to the stealer for a new program. I was told this new program will make the valve less sensitive and stop tripping the SES light. BTW blocking and fingering will not solve the P0403 code.

 

[Moorespeedr]

My 06 has done this for quite some time. The first time it started this business, the dealer replaced the EGR valve. We had been running some VERY nasty fuel out in Louisiana while doing demolition/cleanup after hurricane Katrina. So I figured it was only a matter of time before the EGR valve went out. That crappy fuel got the injectors and the EGR valves in three of my powerstrokes out there, but never bothered my three LLY engines DMaxs. 6 months after returning home, the one I'm driving started throwing out the P0403 code. While at the dealership for a service, they replaced the EGR valve.
6 months later, the code is showing up again.

I am glad to have found this site so I know what to do next......pull my Bully Dog out of the truck and talk to the service manager about an update for the PCM.

Thanks guys.

 

[Bob La Londe]

Hey Guys,

I want to put my two sense in also. I have an 06 that is throwing the same code. I done a lot of checking around, because my truck is out of warranty, and the egr valve is not defective. Basically the valve is not sensing the correct position, thus throwing the code. Go with what Dmax500 said and take it to the stealer for a new program. I was told this new program will make the valve less sensitive and stop tripping the SES light. BTW blocking and fingering will not solve the P0403 code.

I'm glad to see this. I have been having the P0403 code for a year of and on, and the first advice I got was to block and finger stick, but when I checked Kennedy's block/stick FAQ this is also what they say.

Q: I have a DTC P0403
A: P0403 is an indication of a problem with the EGR Servo motor electronics and is
unrelated to the Finger Stick which will neither cause nor cure this code.

I guess I check with the dealer first to see if I have the latest program update.

 

[duramax07tmd]

When my truck had 12k miles on it stock this happened to me. I had a bad egr valve. It was replaced by the dealer and has not been a problem since.

 

[signman1984]

my truck just developed the engine code as well... I can't help but wonder if some excessive idling is the root cause. I have 65k miles on it now and two weeks ago I ended up idling for about 2 hours in the parking lot trying to leave the Renaesance Festival. Not to mention the bumper to bumper trafice getting there that traveled at about 2-5 mph for about 20 miles... We ended up staying at the festival for 5 hours and spent 7 hours in the truck... Anyway, since then I am seeing the engine code. Further more right about the same time I have noticed that the glow plug lite woln't turn off. I know it has gotten cold but I would say that if it don't go off after 60 seconds... it aint gonna. anyway both these issues have kind of developed together. Tomorrow I will stop and have the codes read. If anyone has had similar issues, please advise.

 

[ragbagz]

Hi guys. Somewhat new to the forum. My '06 kicked this code out earlier this week. It just turned over 90,000 miles and all stock. After reading some threads on here I have a little better understanding of what it is. First I will reset the code and see if it kicks it back out again. Is checking the EGR something I can do? Someone mentioned a service bulletin, is there a number? What is blocking and fingering?

Thanks for the info.

 

[Bob La Londe]

Blocking prevents the EGR from venting exhaust gas back into the intake system. A finger stick is a wiring harness hack that prevents the codes that result from blocking from being displayed. Neither will cure P0403 codes. My experience has been P0403 come from a defective EGR or a really dirty egr. Supposedly some models have a program that is over sensitive to egr position and it throws P0403 codes when it probably shouldn't Somebody mentioned that there is a factory computer update that fixes that. They just plug in and reflash the computer. There are a number of programmers and/or computer updates that will program out the EGR troubles codes. Some reccomend adding the blocker plate, and others claim that with their program the EGR never opens so a blocker is not needed.

 

[Chevyguy08]

there is a bulletin on the egr motor malfunction for the 07 classics you can either have the motor replaced or just block it and get a tuner to turn the codes off