Hesitation upon initial accelleration

[vicnation]

I have a 2006 Yukon Denali XL. When I accellerate from a stop, there is a pause for around 4 seconds and then it accellerates hard. A traction assist message appears on the dash during that time. Also, after just having stopped for a traffic light, the brake pedal will pop up against my foot like something mechanical is happening. Could these issues be related to speed sensors at the wheels?

 

[Scottydoggs]

best to start off with getting it scanned for abs codes, need a real scanner for that, but its way better then tossing cash and parts at it hoping its fixed.

things it could be, bad ground on the frame under the drivers foot area. or the abs pump module is broken. they are rebuildable even diy if your up to some soldering. it just sucks to remove cause it under the drivers seat off the frame. theres vids but them little torx bolts like to strip out due to being rusty most of the time.

my hoe does the same thing pretty much, if one wheel spins even a little bit the gas pedal goes dead for like 4-5 seconds. im pretty sure its my abs pump module, i found if i just turn off T/C it does not do it. we also have stability traction control. if you push and hold the t/c button for 8 to 10 seconds the dash should tell you stability control is off, or its not working like mine does. so i just push it the one time and off i go.

 

[vicnation]

Thank you for the information. I'll definitely look into it. BTW, there are no codes in the system.

 

[Scottydoggs]

Thank you for the information. I'll definitely look into it. BTW, there are no codes in the system.

no codes with abs scanner? your normal scanner only shows P codes. abs codes are U codes, and are stored in a history part that the abs scanner can see. most of the time theres a boat load of codes in history, so you clear history, then drive and when it happens again, re scan and those are the relevant codes to follow up on.

 

[Joseph Garcia]

@Scottydoggs is talking about a quality bi-directional scanner. Not only does it provide you with codes that cheaper unidirectional scanners cannot recognize, it also allows to to actually test various modules on your truck to see if they are performing as they should.

 

[vicnation]

I only have a BlueDriver. Do you have any recommendations for a bi-directional scanner that's affordable?

 

[Scottydoggs]

abs scanners are not cheap really. might be best to stop at a shop and ask if they can scan it for ya. dont be surprised if they want to charge you for the scan.

the few times i've need one the garage right across the street from me will just hand me his snap on scanner and let me have at it for free. talk about being lucky there. i have spent a load of money there over the years tho. not like we are pals or nothing lol

 

[Joseph Garcia]

A clone Tech 2 will run you about $350-$450, and an Autec will run you about $500. The Autec is probably a better strategic purchase for new models of vehicles.

 

[Doubeleive]

it should be noted that abs/srs codes almost always self-clear themselves upon a key cycle, if there is a intermittent problem
say when you hit a bump in the road or accelerate/brake, etc
you want to scan for that type of code when the light comes or has come on even briefly before the vehicle is shut off
they are not OBD systems, but are "read/written" thru the obd diagnostic port
if the problem is constant then you have a light on and/or drive-ability issue's and a persistent code (unable to pass-self checking)
otherwise upon a key cycle the code is normally gone
it's also why cheap scanners won't read abs/srs, it requires additional hardware/software which makes it cost more to produce the product

 

[Scottydoggs]

it should be noted that abs/srs codes almost always self-clear themselves upon a key cycle, if there is a intermittent problem
say when you hit a bump in the road or accelerate/brake, etc
you want to scan for that type of code when the light comes or has come on even briefly before the vehicle is shut off
they are not OBD systems, but are "read/written" thru the obd diagnostic port
if the problem is constant then you have a light on and/or drive-ability issue's and a persistent code (unable to pass-self checking)
otherwise upon a key cycle the code is normally gone
it's also why cheap scanners won't read abs/srs, it requires additional hardware/software which makes it cost more to produce the product

the light may clear on the dash, but that codes stored in history.