ABS and Servic Brake System light

[48fleetline65]

I have the same problem with the old Predator, I am thinking of trading in for an intune but would like to know that if I spend another 300 dollars I wont have the same problem

[CHSBowties]

I have an 03' 2500HD 6.0L gas motor, I've had these lights on in my truck for several years and run a Hypertech power programmer that I bought back in 2003, 6 months after I bought the truck to correct the transmission shifting when I put on larger tires.

My truck has the purple "hydro-assist" power brake booster (runs off the power steering pump). A couple years ago, I replaced my booster with a junk yard unit, disconnected the battery to reset the codes, pedal pressure came back (felt like I had full power brakes again) worked for a week, as soon as the pedal got firm again, the lights came back on. The lights (messages on DIC), stay on, I have an InTune and have checked for codes, but none show up.

Try increasing your idle, I noticed when I put the InTune on my truck the idle was too low, not as low as with the Hypertech, but lower than no tuner and had virtually no power steering at idle. I haven't tried replacing my power steering pump, or even my booster with a reman unit, as they are all pretty expensive parts, but my thoughts are it has to do with one of the following things.
Idle speed
Low Vacuum (like if you are running a big cam, or the results of a tuner on ignition timing)
Bad booster or power steering pump
Some pressure sensor in the Hydro-Boost that I think is a non-serviceable part

I'll try disconnecting the battery on my truck with the idle increased via the tuner and see if it makes a difference later this week.

Haven't had anything else to do with my InTune, as I'm still waiting on Diablo to develop the tune for my wife's 2006 GMC Envoy Denali, so I thought I'd try it in place of my 10 year old Hypertech.

[randyc]

I'm really starting to think there is no fix for this and I also don't think this is just some lights to ignore. This morning I had to brake hard because of an idjit who ran a stop sign. The lights had not turned on yet (usually happens 10-20 minutes in my drive), when I slammed on the brakes they resisted (I have spoke about this in another post). I had to let up some and then re-apply.........twice to stop. Thankfully the other fool didn't run all the way into the intersection. If he had, I never would have stopped in time because I had to "pump" the pedal.
Bottomline is I like this product and the power produced, but not to the extent I will die in a car wreck for it......................so either we get a fix or how do I get my money back?

[randyc]

one other thing....................once the light comes on, the brakes work fine. Not an expert, but has to be something to do with the ABS

[cbwallace]

Fingers crosed, but a custom tune from Lew appears it may have fixed this issue for me! I only have 66 miles on the custom tune, but I have not had the ABS light come on at all. Prior to the custom tune it would come on within five miles on every single drive. Performance is also better!!!

Thanks Lew!!!

Chris

[randyc]

keep us posted, 66 miles is definately a plus!

[cbwallace]

150+ miles and no ABS issues. Previously I had experienced many of the same issues others have posted.

[randyc]

that sounds encouraging, but really don't think after paying 400 bucks I should have to send someone another 150 just to fix their product. Going to have to do something though and soon....................my brake pedal thing reared its head again and this time during a turn into a crowded parking lot.
I have noticed no more comments from Diablo staff, guess to busy working on Chyrsler stuff to get new customers...................they already have my money

[CHSBowties]

It's been a month now since I turned up the idle on my 2003 w/ 6.0L and the lights have not returned! I must admit though I've probably only driven the truck 10 times for about 150 miles, but I've driven it in a variety of conditions including 4-lo.

Lew what did you set Chris' idle at on his tune, +100rpm?

[06MonteSS]

I didn't change his idle at all, it's still at stock settings...

I generally don't change the idle at all in tunes...

[randyc]

I just re-adjusted my idle (when running at speed, not stops) to +100, will report back to see if this does anything.......

[06MonteSS]

I had a guy just this past week with this issue on his 2007 truck... he fixed it by modifying the tune and setting the axle ratio, and then measured with a tape measure his tire height/diameter - his tire diameter measured 31.25", so he entered 31.5" in the tire size setting - then he reinstalled the tune with those axle ratio and tire size setting changes, and he has been fine so far, no more ABS/Brake light issues...

[randyc]

Monte,
I have done the part about entering the wheels size manually. What should the axle ratio be set at?
Mine is a Z71 4x4 w/5.3, four speed auto........

[randyc]

Monte,
I found it, mine has a code of GT4 (3.73). I re-adjusted to that (currently was at 3.72)...................also did the tire thing again. I have twice now three times reset that. It keeps going back to 36"(??????????>), hopefully it will stay on the correct setting this time.
Will report results tomorrow AM. Man I hope this works!!!!!!!

[06MonteSS]

correct, you would enter your axle ratio, so 3.73... his was at 3.72 as well initially, and he set his to 3.73

yeah, when you go back into the tire size setting, I don't think the tool shows/remembers what the setting was that you changed it to before, it just defaults to that setting on the screen... so re-entering your measured tire height was the correct move there...