2007 Tahoe 5.3l AFM DOD delete thread

[iamdub]

I figured that be the next thing to do that I may have a shop handle. How's the difficulty of that? Would throwing a newer tyranny in be a wise choice also?

Tranny has to come out. This is why I pulled the engine when I did my AFM delete. I replaced all the gaskets/seals. Also upgraded the torque converter since it was right there. May as well replace the rear cover gasket and barbell while you're at it, too. The rear cover is like the front cover and oil pan- it has to be installed within very tight tolerances and centered on the crankshaft so that the new seal doesn't fail in short order.

If your trans is fine, I wouldn't replace it because it's out for a rear main seal leak.

 

[iamdub]

So far after replacing oil pump, and installed newer oring(green) my low oil pressure has been solved. So I can finally say this AFM delete was a success and hope this thread can help years to come with my questions and the answers given by you fine gents. Special thanks to Iamdub and Wsteele stayed the whole process with me.

Glad it's done! What are your pressures now?

 

[Taheezy_88]

Glad it's done! What are your pressures now?

30-40psi at idle and 60psi hwy sometimes more. Tahoe runs good but I'm pretty sure I need to go back tighten up the exhaust manifold Get a ticking sound

 

[ShootinHeavies]

So I just had my 2011 tahoe swapped with BTR stage 2 cam and now get service brakes soon light. It doesn’t store the code and only comes on randomly, and clears with key cycle. Anyone ever run into this? Everything normal before, swapped vacuum sensor at brake booster and no change.

 

[wsteele]

Probably should have started your own thread.

Do you think the service brake soon message is related to the cam swap?

 

[ShootinHeavies]

Yeah, wasnt sure if being new would get a thread going. The service brakes light only came on after the cam, no issues with the vehicle before. DOD was tuned out for years before the swap, the light is random but usually comes on after tapping the brakes and then putting pressure on it to stop the vehicle at idle/low rpms. We've tried to swap sensors, checked all hose connections, vac gauge test good overall but does stumble a little when tapping/pressing brakes at idle.

 

[Geotrash]

Yeah, wasnt sure if being new would get a thread going. The service brakes light only came on after the cam, no issues with the vehicle before. DOD was tuned out for years before the swap, the light is random but usually comes on after tapping the brakes and then putting pressure on it to stop the vehicle at idle/low rpms. We've tried to swap sensors, checked all hose connections, vac gauge test good overall but does stumble a little when tapping/pressing brakes at idle.

If it helps, I have the same cam and no issues like you're describing. I did the work myself though. Makes me wonder if your brake booster hose to the intake got nicked. I can imagine a vacuum leak in that hose causing symptoms like this.

 

[wsteele]

Yeah, wasnt sure if being new would get a thread going. The service brakes light only came on after the cam, no issues with the vehicle before. DOD was tuned out for years before the swap, the light is random but usually comes on after tapping the brakes and then putting pressure on it to stop the vehicle at idle/low rpms. We've tried to swap sensors, checked all hose connections, vac gauge test good overall but does stumble a little when tapping/pressing brakes at idle.

You should create your own thread so it gets the attention it deserves. It seems to me to be a pretty low probability the new cam is causing the problem.

The vacuum you are getting is highest at idle or off the gas slowing down, so it may not be a vacuum related issue. The fluid level sensor can also go bad. If it thinks brake fluid levels are low, it will illuminate that message.

In my shop manual, it calls out using a Tech 2 (or equivalent) scan tool to test the brake fluid level sensor, nothing about normal resistances or voltage you could test the sensor with a simple multimeter.

Do you know anyone near you that has a Tech 2? You might check the Tech 2 Owners Map sticky to see if someone is close by that can do some debug for you.

 

[ShootinHeavies]

We found a very small intake gasket leak, (the shop reused the factory ones) but not sure if thats enough to cause this. Put a Snap on unit on it and ran through everything, no codes and all sensors mentioned tested fine. The last time it threw the light on, i was backing down the drive way and the brake pedal went soft for a couple of seconds and then normal again, Tahoe drives great, abs functions as it should. Its idleing at aroun 650-700, and sometimes feels like its stumbling when in gear at stop light etc. We are gonna pull the intake and new gaskets, put some gauges on it agian and see what happens. On another note, could some of this be casued by the car settling into new tune? I had DOD tuned out via Diablo for years, untunned at the shop that did the work and they then tuned ECM and TCM with HP tuners. appreciate the help.

 

[wsteele]

We found a very small intake gasket leak, (the shop reused the factory ones) but not sure if thats enough to cause this. Put a Snap on unit on it and ran through everything, no codes and all sensors mentioned tested fine. The last time it threw the light on, i was backing down the drive way and the brake pedal went soft for a couple of seconds and then normal again, Tahoe drives great, abs functions as it should. Its idleing at aroun 650-700, and sometimes feels like its stumbling when in gear at stop light etc. We are gonna pull the intake and new gaskets, put some gauges on it agian and see what happens. On another note, could some of this be casued by the car settling into new tune? I had DOD tuned out via Diablo for years, untunned at the shop that did the work and they then tuned ECM and TCM with HP tuners. appreciate the help.

I seriously doubt a small intake leak or any tune parameters are going to trigger the service brake message. Fixing an intake leak will make it run better though. It will lope a little more with a bigger cam, so maybe that is what you are feeling, @Geotrash could confirm or dispel this last idea though. Also, with tuning, it is all about the skill of the guy filling in the boxes.

There were a few threads a while back on the service brake message, one turned out to be a simple low fluid level, but the other had something to do with a bad O-Ring in the vacuum booster assembly. My search skills are poor, but you might try finding that one.

I think one thing you might try to help in diagnosing the issue is not think about the cam swap when you are thinking about the brake issue. It likely is just a coincidence it happened shortly after the cam swap. It could be related, but the odds are a lot greater it is something else.

 

[Geotrash]

I seriously doubt a small intake leak or any tune parameters are going to trigger the service brake message. Fixing an intake leak will make it run better though. It will lope a little more with a bigger cam, so maybe that is what you are feeling, @Geotrash could confirm or dispel this last idea though. Also, with tuning, it is all about the skill of the guy filling in the boxes.

There were a few threads a while back on the service brake message, one turned out to be a simple low fluid level, but the other had something to do with a bad O-Ring in the vacuum booster assembly. My search skills are poor, but you might try finding that one.

I think one thing you might try to help in diagnosing the issue is not think about the cam swap when you are thinking about the brake issue. It likely is just a coincidence it happened shortly after the cam swap. It could be related, but the odds are a lot greater it is something else.

It's interesting timing, but I haven't driven my cammed truck in a few weeks, but did drive it today. As I was backing out of the driveway and hit the brake, it felt like my brake pedal was skittering like the ABS had been activated. And thinking back on it, I remember feeling it a couple of other times since the cam swap but I dismissed it. No lights or codes though. I'm wondering if it's something about the lope of the cam varying the intake vacuum in such a way that it's either making the brake pedal feel like the ABS is being triggered, or perhaps it actually *is* being triggered somehow. I would need to learn more about the details of how the ABS system gets its signals to activate to see if the latter hypothesis holds water.

 

[ShootinHeavies]

I seriously doubt a small intake leak or any tune parameters are going to trigger the service brake message. Fixing an intake leak will make it run better though. It will lope a little more with a bigger cam, so maybe that is what you are feeling, @Geotrash could confirm or dispel this last idea though. Also, with tuning, it is all about the skill of the guy filling in the boxes.

There were a few threads a while back on the service brake message, one turned out to be a simple low fluid level, but the other had something to do with a bad O-Ring in the vacuum booster assembly. My search skills are poor, but you might try finding that one.

I think one thing you might try to help in diagnosing the issue is not think about the cam swap when you are thinking about the brake issue. It likely is just a coincidence it happened shortly after the cam swap. It could be related, but the odds are a lot greater it is something else.

I have a crew 06 5.3 thats running a TSP chop monster and all supporting mods, so what it feels like isnt the cam. I am looking at anything other than the cam now, just really strange timing for this. But we are gonna get into it further this weekend and see.

The shop that tuned the Tahoe tuned my 06 several years ago when I installed it, I just didn't have the time to do this swap and had them do it instead.
They do quite a few of these, and other associated mods, so I dont know if its the tune either.

 

[ShootinHeavies]

It's interesting timing, but I haven't driven my cammed truck in a few weeks, but did drive it today. As I was backing out of the driveway and hit the brake, it felt like my brake pedal was skittering like the ABS had been activated. And thinking back on it, I remember feeling it a couple of other times since the cam swap but I dismissed it. No lights or codes though. I'm wondering if it's something about the lope of the cam varying the intake vacuum in such a way that it's either making the brake pedal feel like the ABS is being triggered, or perhaps it actually *is* being triggered somehow. I would need to learn more about the details of how the ABS system gets its signals to activate to see if the latter hypothesis holds water.

This is exactly whats happening when it triggers the message, and its very random. Otherwise it runs great and functions normally.

 

[Geotrash]

This is exactly whats happening when it triggers the message, and its very random. Otherwise it runs great and functions normally.

Same - it's totally random on mine too. The only difference is I'm not getting any messages.

 

[wsteele]

It's interesting timing, but I haven't driven my cammed truck in a few weeks, but did drive it today. As I was backing out of the driveway and hit the brake, it felt like my brake pedal was skittering like the ABS had been activated. And thinking back on it, I remember feeling it a couple of other times since the cam swap but I dismissed it. No lights or codes though. I'm wondering if it's something about the lope of the cam varying the intake vacuum in such a way that it's either making the brake pedal feel like the ABS is being triggered, or perhaps it actually *is* being triggered somehow. I would need to learn more about the details of how the ABS system gets its signals to activate to see if the latter hypothesis holds water.

The plot thickens.

Was the Denali you added that cam to a DoD engine (couldn't remember)? If so, did you do anything with the AFM sensor on the Brake Booster?

 

[ShootinHeavies]

Same - it's totally random on mine too. The only difference is I'm not getting any messages.

So we got into it a bit Sunday, replaced bad intake gaskets. The vacuum gauge reads 9-10 at idle of 670 rpm which jumps from 575-670 rpm, the gauge reads 10-14 at 800 rpm and 12 on the MAP sensor VIA snap on unit, seems vacuum is really low

 

[Geotrash]

The plot thickens.

Was the Denali you added that cam to a DoD engine (couldn't remember)? If so, did you do anything with the AFM sensor on the Brake Booster?

Yes it was, and no, I did not. Hmmmm…

What, if anything, should I do with it?

 

[wsteele]

Yes it was, and no, I did not. Hmmmm…

What, if anything, should I do with it?

Your guess is as good as mine. I only discovered it was there when I started to dig into this thread.

I honestly think if it was the source of the problem, it would be flagged as something to attend to when doing the delete. I mean, a lot of these have been done by now.

But then again…

 

[Just Fishing]

When i did the dod delete on my 5.3, i got weird errors the first startup
stabiltrack errors, brake errors, etc.
super weird.
Found two things.
First when i did the dod delete, i needed to turn off errors for the DOD sensors in the tune.
Then i had a reduced power message related to me cleaning the throttle body, I did the learn via tech2 to resolve.

 

[swathdiver]

So we got into it a bit Sunday, replaced bad intake gaskets. The vacuum gauge reads 9-10 at idle of 670 rpm which jumps from 575-670 rpm, the gauge reads 10-14 at 800 rpm and 12 on the MAP sensor VIA snap on unit, seems vacuum is really low

That's not enough to operate the brake booster. You need at least 18 inches of vacuum in my experience. I just checked my shop manual and the computer converts the vacuum signal to voltage so I don't know the exact specs for our trucks. If the camshaft turns out to be the problem and you desire to keep it, you might look into a hydroboost conversion.