ABS problems with tires over 34"

[McRat]

Any chance of getting my speedometer to read anywhere close??? I have tried the tire size.....revs per mile....everything. But the speedo still reads 13 MPH off. Eg. 60MPH is actually 73MPH. Efi techs, are supposedly working on a fix. But its been 6 months.

Does EFILive alter the speedo reading at all?

 

[The Neens]

I could have sworn I did an 07, I think it was an LBZ.

Stop by if you are in the area and we can dink with it.

Perfect, thanks...I'll be in the 951 on Sat.

I'll call the boss on my way into town

 

[RayMich]

What are the Tech2 ABS choices for smaller tires?

Does it have specific ABS choices for the standard OEM sizes (215/85-16, 245/75-16 or 265/75-16)? or is it just 245/70R-19.5 for anything under 33 inches?

Thanks.

 

[Lennart]

I got my hands on a Tech2 today and tried changing the tire size. For some reason it did not work. I also had no tire size programmed.
Anyone experience the same?

 

[MANDOMAX]

I am running 35" tires and 4:56 gears with the PPE programmer. I had the ABS light come on just after installing both tires and gears on my way home. Punched in 4:56 for the gear ratio then had to play with the tire size to get the speedo to mark the correct MPH. Marked 33.5 for tire size. I have never had any problems since.

 

[The Neens]

I got my hands on a Tech2 today and tried changing the tire size. For some reason it did not work. I also had no tire size programmed.
Anyone experience the same?

I had this problem on a '08 last Summer...A friend updated my Tech II and it worked after the update...

 

[8lug]

I run a Bully Dog and 36s I have never had an ABS problem (130k miles) but if I switch to EFI will this change???

 

[Ten_Bucks]

Learned this the hard way this morning with the '07.5 LMM I worked on. Truck runs 37s with the stock gear ratio and I had to set the PPE to 34.75" tires with the stock ratio. Its working well so far. Eventually the truck will get a gear ratio change to 4.10s.

Scott

 

[rebel7777]

Does EFILive alter the speedo reading at all?

Yes, did it on my 04.5. Went from 245's to 275's, recorrected the speedo just fine. No issues. But now I have the dreaded ABS issue.

 

[rebel7777]

I run a Bully Dog and 36s I have never had an ABS problem (130k miles) but if I switch to EFI will this change???

Your bullydog is showing the right speed correct? but your speedo is still out?

EFI allows you to change the pulses per mile, that seems to be where the issue exists when you change your speedo for the larger tires with EFI. So the answer is if you don't change your pulses per mile you should be fine if the problem doesn't exist now.

 

[smarquis]

Just stumbled upon this. Just got my truck back from getting the turbo installed, and I had this issue for the very first time. (I also received an updated PPE programmer, so I assume that had something to do with this issue.) Ironically, I put in 4:10 gear ratio and 33.5" tires, and it seems to have cured the problem (gear ratio is stock 2:73, and tires are more like 34"). And, the speed apears to be about right! Thanks for the post. When I was having the problem but it wasn't throwing any codes, i was really confused.

 

[Too Many Projects]

So has it ever been determined if there is a fix for the '07.5+ trucks? I had no issues when with 37s & stock gears but after I went up to 40" tires & changed the gears out to 4.56's I got the ABS & brake light (also disables the park sensors & gives a "service trailer wiring" message). I corrected the speedo with EFI & because I was aware of the issue before hand, I got a hold of a Tech 2 to change the ABS setting. I used it to check the PID's & verify that the front & rear wheel speeds are reading very far off from eachother. However it would not allow us to change the ABS setting (in the ebcm). The only thing I could come up with is a bulletin stating that you could get a VCI number from GM to correct any ABS issue if you bought there GM accessory 22" wheels.
Am I just trying to change the wrong thing? Or do I have to change the tire size with the Tech 2 first (because it will cal for the speedo & ABS?), then correct the speedo with EFI (since that will only alter the speedo sensor & not the ABS?)?

 

[Tekker]

So has it ever been determined if there is a fix for the '07.5+ trucks? I had no issues when with 37s & stock gears but after I went up to 40" tires & changed the gears out to 4.56's I got the ABS & brake light (also disables the park sensors & gives a "service trailer wiring" message). I corrected the speedo with EFI & because I was aware of the issue before hand, I got a hold of a Tech 2 to change the ABS setting. I used it to check the PID's & verify that the front & rear wheel speeds are reading very far off from eachother. However it would not allow us to change the ABS setting (in the ebcm). The only thing I could come up with is a bulletin stating that you could get a VCI number from GM to correct any ABS issue if you bought there GM accessory 22" wheels.
Am I just trying to change the wrong thing? Or do I have to change the tire size with the Tech 2 first (because it will cal for the speedo & ABS?), then correct the speedo with EFI (since that will only alter the speedo sensor & not the ABS?)?

Epic almost 1 year bump but curious to see if anyone has figured out if this works for the 07.5+ trucks. Been reading all morning but I havent gotten a definitive "Yea or Nay" as to if this can be corrected. I have a Cog 7-9 on order as well as some 37" Toyo's and I'm definately having second thoughts after reading all these horror stories. I just dont want to deal with any more dash lights... (F*&K you, TPMS )

 

[Trippin]

Set the Speedo and gear selection back to stock with EFILive and plug a Hypertech 730102 into the harness behind the speedo cluster. Program the 73102 to what ever you want as far as gears and tire size goes.

I've used this method dozens of times...............

 

[Tekker]

Set the Speedo and gear selection back to stock with EFILive and plug a Hypertech 730102 into the harness behind the speedo cluster. Program the 73102 to what ever you want as far as gears and tire size goes.

I've used this method dozens of times...............

Awesome! Thanks for the heads-up! :hug:
I assume this keeps everything working in harmony since EFI maintains a stock setting yet the speedo reads correct via the hypertech. Only thing I'm wondering is, what prevents the ECM/BCM from freaking out when they see a missmatch from the stock tables. Dont they compare what they should "see" vs actual via the VSS and if there is a miss match (running a 37" tire on stock tables), it will throw ABS codes along with trailer brake systems deactivation?

 

[Trippin]

That particular Hypertech module (plugs in right behind the cluster and stays there) is modifying the signal after the ECM/ABS/BCM have seen it, right before it goes into the cluster. So as long as all of the tables in the ECM are set to stock, everybody gets along and your speedo is correct.

The reason the codes set in the first place is the ABS module is seeing too great of a difference (usually about 5 mph) between the two front wheel speed sensors, and the rear speed sensor on the back of the trans or transfer case.

Clear as mud?

 

[S Phinney]

I haven't had a single issue with my 03 with 35" or a 07 with 36" tires that I tune.

Sent from my DROID RAZR using Tapatalk 2

 

[Tekker]

That particular Hypertech module (plugs in right behind the cluster and stays there) is modifying the signal after the ECM/ABS/BCM have seen it, right before it goes into the cluster. So as long as all of the tables in the ECM are set to stock, everybody gets along and your speedo is correct.

The reason the codes set in the first place is the ABS module is seeing too great of a difference (usually about 5 mph) between the two front wheel speed sensors, and the rear speed sensor on the back of the trans or transfer case.

Clear as mud?

That makes more sense, I was just confused as to why it wouldnt set the code with stock tables (which are programmed for 245/75R16s on a stock truck). Wouldnt the ECM/ABS/BCM detect a missmatch between what it should see VSS-wise and what it DOES see with a 37" Tire - 37" tire being larger diamater so less rotations per MPH? Thats where I'm getting confused, I think. I just assumed the hypertech is just a bandaid to make the speedo read correctly. Sounds like something I'll have to invest in if and when I hit this wall. Thanks Guy!

I haven't had a single issue with my 03 with 35" or a 07 with 36" tires that I tune.

Sent from my DROID RAZR using Tapatalk 2

Apparently this is a common issue with only the 07.5-08 (new body style) and possilby the 09 trucks. 07 and below dont have this issue.

 

[2006coalroller]

Did my lmm with Wfo 37 4:56 no abs

 

[Tekker]

Did my lmm with Wfo 37 4:56 no abs

That gives me some hope then that possibly I'll luck out and not have to deal with this crap. I take it that you set the tire size to 37 in EFI?

Got the tires in today and holy crap theyre giant compared to 33's LOL