Code 35

[syclone1100]

:rant: So I have been figting with this code for awhile now and its got me completly irritated.... So a code 35 is idle speed error, I allready have replaced the IAC valve(2x), EGR valve, and checked for vacuum leaks (none holds at -18 to -20) Ive tried adding fuel and leaning it out(reset ecm after every fix).. Nothing has fixed it :banghead: the only time it comes on is when the truck is either in park and idles for a little while or when stoped at a light for a little while once the truck starts to move again the code goes away.. On occasion after a hard acceleration the truck gets a surging idle of about 500rpms but no code is thrown.. The only thing I havent tried is replacing the stock cat and replacing it with a 3" since the Dp and exhaust(excluding the cat) is 3"... I dont know what else to look for or fix.....

 

[Bill Z]

Re: Code 35

Just a thought here but maybe your injectors. I've seen where 1 or more injectors leak to where you run rich at idle causing the engine speed to increase.

You didn't mention your idle RPMs. If your RPMs are high (ergo the code) then think about a fuel leak.

One way to check the injectors is to mesure your rale pressure while running and at 2 minute intervals after you shut it off. The rale pressure should not drop much unless an injector is leaking.

Let us know what you find out and good luck.

 

[SonomaGTlover]

Re: Code 35

Symptoms seem very similar to issues I am having....

I have seen the light come on and go off as you mentioned but have not checked for codes. My idle occasionally bumps up to 1500 or more for no real reason that I have found. (in gear it remains 800 or so) Something is screwing with the IAC because I can remove it, adjust it by hand and replace it then the truck is fine for awhile. I have cleaned it and it seems to be working because if i adjust it too far out, then it takes over and corrects the idle fine. I also have a 500-600 rpm surge when decellerating at lower speeds. I used to chalk this up to shift points in and out of higher gear but think it may be related somehow.

I have not yet checked for fuel leak as mentioned and will certainly check it out. Thanks for the idea... If I understand correctly.... put the gauge on the fuel rail and run the truck. Turn off the truck and check pressure reading every 2 min. if I see significant drop then I have a leak....correct?

PS... I haev 50#, no cat and egr delete.

 

[syclone1100]

Re: Code 35

I have a fuel press guage and it stays steady, but does rise about 2lbs under accleration, I'll keep a closer I on it and I'll try and get a Dm log and post it to see what else it might be..... anyone else have any ideas?????

 

[nello]

Re: Code 35

:rant: So I have been figting with this code for awhile now and its got me completly irritated.... So a code 35 is idle speed error, I allready have replaced the IAC valve(2x), EGR valve, and checked for vacuum leaks (none holds at -18 to -20) Ive tried adding fuel and leaning it out(reset ecm after every fix).. Nothing has fixed it :banghead: the only time it comes on is when the truck is either in park and idles for a little while or when stoped at a light for a little while once the truck starts to move again the code goes away.. On occasion after a hard acceleration the truck gets a surging idle of about 500rpms but no code is thrown.. The only thing I havent tried is replacing the stock cat and replacing it with a 3" since the Dp and exhaust(excluding the cat) is 3"... I dont know what else to look for or fix.....

Syclone11, are you still driving this truck? did you get this prob fixed? Think I'm having a similar or same issue. I was just about to fire up my truck when I was getting DM ready and it started pinging like mad. ding ding ding! So something is already wrong and I haven't got it started yet?
Just trying to record a DM file and I'm seeing under the "engine dtc" window..."MALF 35: IAC Error", cell number 3,5.
Recently (last 2 or 3 drives) my speedo kept dropping to ZERO after driving for 5 or so minutes. Shows no speed. Shut it off, speedo comes back...for five or so minutes. Anyone? I'm just now getting some time to look, hopefully today.

Only changes since it seemed to drive normal was I put my ECM in the glovebox, done it before on other truck=no problem.
:idea: I'm going take a run :turbo:, get some coffee, switch out to a different chip, and see if my scan picks up anything. Any info you guys may have please get it on here and get this thread rolling again so I can fix my proplem I'd appretiate! Thx.

 

[nello]

Re: Code 35

Anyone?

 

[nello]

Re: Code 35

Hello?

 

[turbodig]

Re: Code 35

Most common code 35 causes:

Bad/plugged IAC
Somebody messed with the throttle plates.
Vacuum leak
Really bad fueling (like bad enough to set other codes)
DRAC + VSS screwed up/loose wires causing inconsistent VSS signal.

What do your IAC steps do when the problem happens? Also, is MPH in the scan tool moving around at rest or not moving around at speed?

 

[nello]

Re: Code 35

Thanks, I;ll be sure to check all that out Dig. I was able to get the code to go away. I unplugged the battery for about a minute and then rescanned. The problem was gone. Usually when I start a scan, like last night for instance, I only turn the ignition switch on...no engine start up. I then go through some checks like TPS for instance and look for DTC errors....35 was what popped up without the truck running, pinging the DM alarm like MAD! I don't believe the MPH are bouncing around but I'll have to wait for it to error out again to check.

I must have a short somewhere, I think DRAC + VSS screwed up/loose wires causing inconsistent VSS signal is most likely the cause as you stated. I've recently had some issues with my speedo going out while driving...later it may come back during the drive or maybe take as long as a week. I'm going to check your suggestions out, thanks for the reply. U :guitar: