• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

code 36, Code 35

A

Acesneights1

New Member
Messages
10,018
Reaction score
36
Location
Northeast CT
Trying to help a freind out. It's 94 K3500. Has a DSG relocated PMD on the intake. It had code 78,29,35,36.
78 was a bad WG sol. fixed
29 I think are loose glow plugs(they were so loose they were leaking compression.
Neither code has returned.
It has a mid range stumble and the SES light comes on for a second when stumbling and goes out. It throws a code 36 consistently when this happens. The code 35 has not returned. Truck seems to run good otherwise. Has 94k on it and GM did the IP a few years back.
PMD ??
IP ?

I pulled the PMD and tried tightening the transistors. He is coming to my house Sunday and I am going to try the PMD from the Burb to see if it goes away. What else could that be ?
 
Code 35 36 most likely pmd. If you have no starting problems, stalling, 99.9% sure its pmd. Also, the stumbling (on hard acceleration?) can be a symptom of a bad pmd. If you put in alternate Pmd and still have stumbling you may want to check your lift pump. If the lift pump is out you could be causing the injection pump to be working a bit harder than need be and this will also cause a hiccup during hard acceleration-lack of fuel. Your truck will still run with the lift pump out but causes more strain /heat to the IP.... Hope that helps.
 
Dump a quart of 2 stroke oil in the fuel tank too. Lubricating the IP can help avoid issues with the pulse width codes. As this often ends up being an IP issue. An issue that comes about from dead LPs or using ULSD with no additives.
 
buddy said:
Dump a quart of 2 stroke oil in the fuel tank too. Lubricating the IP can help avoid issues with the pulse width codes. As this often ends up being an IP issue. An issue that comes about from dead LPs or using ULSD with no additives.
Click to expand...

That's what I was thinking as well. I did a bunch of reading on a thread from Texas diesel Guy over at the old site about this. The guy is supposed to bring the truck to my house tommorow for a PMD trial swap but I am going to call him today and tell him to dump a quart of 2 stroke and a double dose of Power Service and see what happens.

BTW...So I can explain it better to him if it is a dead IP why does inj pulse long(code 36) mean a dead IP (if it is). In other words what is going on in there that is failing ?
 
35 and 36 seem to be the generic codes if anything is wrong. All other codes must be cleared to clear 35 and 36. As allways ,grounds,grounds,grounds. Lift pump,sock in tank and fuel cap are suspects.
 
I'm gonna sight glass it tomorrow but I don't think it's a supply issue. The stumble is erratic , in other words sometimes fine sometimes there and it "feels" to me lke a dying IP. gonna go through the motions anyway. I told him to put a quart of tranny fluid in today with a double dose of PS. The grounds looked fine. Wiring looked clean not butchered. Batt cable all tight, no corrsion. Will try a PMD swap tomorrow. I'll check LP while he is here as well.
 
I agree with Buddy and BK, Kenny ... lots of people have permanently (or at least semi-permanently) cured their pulse-width codes by putting a litre of 30wt in every tank. Best part is, you should be doing that anyway with ULSD... and it can't hurt anything.
 
It throws one of these codes when the IP's fuel metering valve to go from full open to full closed is too long or too short. The PCM send a digital pulse width signal to the PMD which switches power on and off to the IP's fuel solenoid. The computer monitors how closely the Fuel Solenoid action matches the commanded pulse. The actual PCM pulse width output to the scanner appears to be the time between when the PCM's pulse cuts out and when the metering valve returns back into the fuel solenoid. It knows how long it should take a fully extended valve to travel back. If its too short it could be that it didnt actually fully travel and if its too long it could be sticking. That is measured in milliseconds.
 
Last edited:
buddy said:
It throws one of these codes when the IP's fuel metering valve to go from full open to full closed is too long or too short. The PCM send a digital pulse width signal to the PMD which switches power on and off to the IP's fuel solenoid. The computer monitors how closely the Fuel Solenoid action matches the commanded pulse. The actual PCM output appears to be the time between when the PCM's pulse cuts out and when the metering valve returns back into the fuel solenoid. It knows how long it should take a fully extended valve to travel back. If its too short it could be that it didnt actually fully travel and if its too long it could be sticking. That is measured in milliseconds.
Click to expand...

Thanks. That is the answer I was looking for. He dumped the quart of 2 stroke in today and double dose of PS. He said the truck was doing it less. We will still try the PMD swap anyway tomorrow and I will sight glass and test FP to rule out all other options before condemning the IP.
 
mine has had a 35 mostly and sometimes 36 for a while now, comes on as I hit around 1500 rpms,,, goes out as soon as I let off the go pedal. Didn't help me with the oil or Dbl on PS. But I did put about 15 gallons of BIO in a few weeks back,, when the gauge was down in the red zone,, I bet it's about a B80 mix,, the light seemed to be on less, and not at all for a few days,, As I'm getting closer to the red mark again,, it seems to be coming back on more. I've gotta fill it up again soon, and I'm done with the bio for the rest of the year. {gonna be in the mid 30's for the next night or two} So it will be back to Dino, and a quart of 30wt. We'll see how that goes, But it runs fine, no stumble or anything, just the cruise ain't working cause of the ses light being on. Hope it ain't the IP,,, I really don't have the cash or want to do a replacement on that now!
 
What you describe is exactly what his is doing. If it is a dying IP any harm in driving it until it pukes or should it be rebuilt right away ?
 
that I don't know,,, I hope it don't hurt it,, as I have to drive it this way for a while,,,,funds are Tight!! I'll prob buy a rebuilt from the shop that did my injectors for me. I'll do the install my self, Hoping it'll last till spring,, Let me know if you find out anything on you buddies ride!
 
You must log in or register to reply here.
Back
Top