got a BIG problem.... p0090 won't go away

[1lowdiesel]

ok here's the story. i just did a PPE dual cp3 kit on an 08 LMM. truck was fine before this, no codes at all. we put the kit on and now there is a hard p0090 code. dan and i have been racking our brain the past 3 days and nothing has worked. this code comes on as soon as the key is turned on, you clear it and it come back right away. at idle FP is 11k psi when it should be about 5 somehthing. i've checked every fuse every wire and still nothing. i unplugged and check every plug that goes w/ the fuel pressure, nothing.

now here is something i found last night, i have no power going to the fuse marked fuel pump (#18 i believe), the relay is fine but no power on either side of the fuse. power going into the fuse box and none of the prongs are bent under the fuse box and none are pushed in. the two big plugs on the motor are fine as well.

has anybody ever come across anything like this before. i'll be on here all day and if someone wants to they can call me after 6e on my cell 732 277-6076. i have a friend coming over tonight that is a GM tech and he has his tech II scanner so hopefully we can something figured out.

in the meantime anybody have any ideas?

thanks in advance guys.

kyle

 

[SmokeShow]

take the dual cp3s off and go back to the way it was before and see if the problem is still there... just trying to do a process of elimination here...

C-ya

 

[1lowdiesel]

did it, right now it's only the stock one hooked up, there is no belt on the truck either so it's not even running the other pump.

 

[duratothemax]

now here is something i found last night, i have no power going to the fuse marked fuel pump (#18 i believe), the relay is fine but no power on either side of the fuse.

that fuse spot is only used on the gas trucks. dmax doesnt have a fuel pump.

 

[duratothemax]

Kyle I would check to make sure you have the dual cp3 controller hooked up correctly, and double check the wiring circuit that goes to from the ecm to the stock CP3 fuel press regulator.

 

[1lowdiesel]

what's strange is that the fuse box says gas on one side and diesel on the other, it has a fuel pump relay and a 10a fuse on the diesel side.

right now the wiring for the dual cp3 isn't even hooked up, the stock plug is plugged into the stock pump.

so basiclly trace the wires from the plug all the way to the pcm by the radiator.

do you think that with the tech II we'll be able to figure something out?

 

[LarryJewell]

have you tried lowering fp at idle

 

[1lowdiesel]

how do you do that?

the truck has a Hot+2 on it.

 

[LarryJewell]

how do you do that?

the truck has a Hot+2 on it.

EFI Live

 

[MMLMM]

are you using stock regulator in the pumps?

 

[1lowdiesel]

yea they are both stock pumps w/ stock regs.

 

[1lowdiesel]

anybody have a wiring diagram for the reg?

 

[MMLMM]

so its doing it still with just stock pump hooked up?

I know its a pain but maybe switch regulator in stock pump with the good one from 2nd pump...see if it woks then.

 

[1lowdiesel]

yea. i was thinking about that but it's a last resort.

if it was bad would it cause the cel to be a hard code w/ just the key in the on position?

 

[MMLMM]

yea. i was thinking about that but it's a last resort.

if it was bad would it cause the cel to be a hard code w/ just the key in the on position?

maybe a short or something. idk tho...

Have you returnd the tune to stock and tried it?

Any other codes or just that one?

try turning the key on, then off, leave the key off, wait about 4-5 minutes then with key off try to pull code, if it dont work turn key on pull and clear code then urn off and re start...
If it like the P009e code (that im very familir with) you have to clear it this way..

 

[05smoker]

We had a similar issue and our return line was kinked causing excess pressure to build from the air dog. We were at about 18k though.

 

[1lowdiesel]

maybe a short or something. idk tho...

Have you returnd the tune to stock and tried it?

Any other codes or just that one?

try turning the key on, then off, leave the key off, wait about 4-5 minutes then with key off try to pull code, if it dont work turn key on pull and clear code then urn off and re start...
If it like the P009e code (that im very familir with) you have to clear it this way..

i'm thinking a short as well but i was working on it till 4:30 this morning and still no luck.

yup returned it to stock quite a few times and tried to clear it it'll flash then come right back on. do you think it could have something to do w/ the programming. i don't but i don't know what else to try.

that is the only code, and it comes up twice once when you turn the key on then again when the truck is running. it'll start then slowly drop to about 10k.


i'll have to try clearing it like that, i'll try anything at this point.

We had a similar issue and our return line was kinked causing excess pressure to build from the air dog. We were at about 18k though.

the airdog isn't even hooked up right now.

 

[MMLMM]

Yea just trying to give you any poss. idea. I dont think its programming but still gotta rule it out to be sure at this point lol.

When you moved the FRPV did you shim/race valve it? Thats wierd its doing it even in stock setup. Leads me to think its the regulator but hate to hav to switch it out if its not. Maybe the tech II will see something.

 

[ripmf666]

that fuse spot is only used on the gas trucks. dmax doesnt have a fuel pump.

At one point in time I saw in Gm info that they were going to install a factory lift pump like the duramax van run.

 

[1lowdiesel]

yea i hear ya, believe me i appreciate it.

nope just relocated it to the block that comes w/ the PPE kit. they give you a racevalve looking thing that has threads on it, then the new fuel line goes into that. then the shimmed valve goes into the distribution block...... if that makes any sense, idk i'm only on 2hrs of sleep

i hope the tech II does something.