What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[kbuskill]

I don't think any of the generic scan tools have the ability, but is there a scan tool out there that has the ability to log or read all four wheel speed sensors? That might assist me in targeting which corner is the culprit.

Not sure where to point you for your issue, as I didn't have any issues with my Belltech spindles, BUT this app...

Check out "ChevroSys Scan Free"
https://play.google.com/store/apps/...elm327.obd2.chevroletsys.chevroletsysscanfree

Will allow you to read and clear ABS codes via your Android phone and a bluetooth OBD2 scan tool... not sure if Apple has anything similar or not.

Hope this helps.

 

[Hi-psi]

Not sure where to point you for your issue, as I didn't have any issues with my Belltech spindles, BUT this app...

Check out "ChevroSys Scan Free"
https://play.google.com/store/apps/...elm327.obd2.chevroletsys.chevroletsysscanfree

Will allow you to read and clear ABS codes via your Android phone and a bluetooth OBD2 scan tool... not sure if Apple has anything similar or not.

Hope this helps.

I have several scan tool options that will read and clear ABS, chassis, powertrain, etc, etc, codes. I've looked through all the data streams on them however and I don't think they have (at least that I've found) the ability to read/display the individual wheel speed sensor data to assist me in zeroing in on which sensor/corner is maybe not reading consistently.

 

[kbuskill]

I have several scan tool options that will read and clear ABS, chassis, powertrain, etc, etc, codes. I've looked through all the data streams on them however and I don't think they have (at least that I've found) the ability to read/display the individual wheel speed sensor data to assist me in zeroing in on which sensor/corner is maybe not reading consistently.

I, perhaps wrongly, assumed that if it was setting a code in the ABS computer that it would tell you which sensor was the culprit.

 

[Hi-psi]

I, perhaps wrongly, assumed that if it was setting a code in the ABS computer that it would tell you which sensor was the culprit.

It's not setting a code. It's simply occasionally activating the ABS during sharp low (less than 10-15 mph) speed turns because at least one sensor is apparently not reading correctly at low speeds thus the system is detecting a variance between the four sensors and engaging the ABS.

Behavior started immediately after the install of the lowering kit, I've confirmed all plugs are secure, and I've replaced all four sensors with no change in the behavior, which makes me think maybe some debris or trash found it's way inside one of the front wheel bearing/hub assemblies when the sensors were removed for the drop spindle install.

 

[Rocket Man]

Will they really yield that much horsepower? I’ve been thinking about installing one but I’m not really trying to drop $200 on something from catchcans.com. Does anyone here have any experience with the cheap Chinese ones on Amazon? A lot of them have pretty good reviews.

No hp gain from the catchcan, just gains from red parts ‘cause red =hp lol.

 

[Doubeleive]

It's not setting a code. It's simply occasionally activating the ABS during sharp low (less than 10-15 mph) speed turns because at least one sensor is apparently not reading correctly at low speeds thus the system is detecting a variance between the four sensors and engaging the ABS.

Behavior started immediately after the install of the lowering kit, I've confirmed all plugs are secure, and I've replaced all four sensors with no change in the behavior, which makes me think maybe some debris or trash found it's way inside one of the front wheel bearing/hub assemblies when the sensors were removed for the drop spindle install.

I wonder if the bcm has a abs activation saved (that a tech2 can read), sometimes the bcm will store things for a period of time even though it hasn't set a code, then if the problem goes away after a set period time it erases them if the problem keeps occurring it can set a code under certain conditions. Higher end scanners will show the individual wheel sensor data as the wheels turn

 

[PG01]

So three or so weeks ago I installed a McGaughy's 2/3-4 drop.

Since the install, I've had an issue of intermittent low speed ABS activation while turning sharply. If I'm on the brakes, the ABS pulses, if I'm not then just the traction control light flashes.

So, obviously a wheel or two is not reporting speed correctly making the system think either a wheel is locking up, or losing traction.

I was out of town for a couple of weeks with work, so in the last few days finally got a chance to circle back on this. I replaced all four wheel speed/abs sensors. No change. Exactly the same behavior. I'm at a bit of a loss now. On the drop spindles on the front, with how where the hub/wheel bearing is located, the sensor is a bit of a tight fit between the spindle and hub, but it's fully seated.

The front wheel bearings/hubs are fairly new (less than a year) Timken units. The only thing I can think of now is that when removing the sensors out of the wheel bearings/hubs while installing the drop spindles some trash or debris got down into one of them and maybe that's causing a funky reading/signal? When I put the new sensors on, I rotated the hubs 360* while looking down inside and they both looked clean.

I'm tempted to just throw a couple of new front wheel bearings/hubs on it and keep the current ones as backups, but I'm open to any other thoughts, ideas, or suggestions before I just throw parts at it.


I don't think any of the generic scan tools have the ability, but is there a scan tool out there that has the ability to log or read all four wheel speed sensors? That might assist me in targeting which corner is the culprit.

If it only happens turning sharply its obvious, to me, that you’re losing a connection somewhere, whether it be a in the hub/sensor itself or the wires going to/from sensor. Go over your wires again.

 

[Hi-psi]

Poked around in my scan tool earlier today and it does have the ability to display all for wheel speed sensors.

Unfortunately, that didn't provide much insight. Found a wide open parking lot where I could safely just drive around in a circle at about 10mph while looking at the scan tool. The whole time the traction control light would flash, but the wheel speed sensors were consistently reading and reading as expected. The inside wheels would read just a bit slower than the outside (as expected) and the rear just a bit slower than the fronts. Similar readings regardless of whether I was making clockwise or counter-clockwise circles. Inside slower than outside by a small amount, rear slower by just a small amount than same side front.

I think my next step is to call McGaughy's tomorrow and just ask if they've ever heard or come across this. Maybe I'll get lucky and they have and can provide some insight or a solution.

 

[HiHoeSilver]

No hp gain from the catchcan, just gains from red parts ‘cause red =hp lol.

 

[Incognito]

Changed out the crusty old emblem

 

[the_tool_man]

Changed the oil in my Yukon today. Installed the Fumoto drain valve. Used my new strap wrench to remove the filter. Wished removing the filter didn't make such a huge mess. Gonna have to get one of those filter punch doohickeys.

Also broke the cap on my oil catch tub. Remember Manly's law of repair? Yeah, me too.

 

[Doubeleive]

Poked around in my scan tool earlier today and it does have the ability to display all for wheel speed sensors.

Unfortunately, that didn't provide much insight. Found a wide open parking lot where I could safely just drive around in a circle at about 10mph while looking at the scan tool. The whole time the traction control light would flash, but the wheel speed sensors were consistently reading and reading as expected. The inside wheels would read just a bit slower than the outside (as expected) and the rear just a bit slower than the fronts. Similar readings regardless of whether I was making clockwise or counter-clockwise circles. Inside slower than outside by a small amount, rear slower by just a small amount than same side front.

I think my next step is to call McGaughy's tomorrow and just ask if they've ever heard or come across this. Maybe I'll get lucky and they have and can provide some insight or a solution.

if you have ride height sensors they (might) need to be adjusted for the drop those are part of the system and may mess with the traction control but probably not the abs

 

[Sam Harris]

if you have ride height sensors they (might) need to be adjusted for the drop those are part of the system and may mess with the traction control but probably not the abs

I thought the issue was ABS activation, rather than TC.

 

[Sam Harris]

Changed the oil in my Yukon today. Installed the Fumoto drain valve. Used my new strap wrench to remove the filter. Wished removing the filter didn't make such a huge mess. Gonna have to get one of those filter punch doohickeys.

Also broke the cap on my oil catch tub. Remember Manly's law of repair? Yeah, me too.

Sucketh. Do not like

 

[97audia4]

Changed trans fluid last night, just dropped the pan and replaced filter. What a ***** that back left bolt is. Also replaced all the aged and cracking wire loom.

 

[Hi-psi]

if you have ride height sensors they (might) need to be adjusted for the drop those are part of the system and may mess with the traction control but probably not the abs

I do, and they've been correctly adjusted.

Fronts require no adjustment by nature of the drop spindles. Rears have been adjusted so that just after staring the vehicle the compressor kicks on for just a second and raises the rear maybe a 1/4 of an inch.

 

[Rocket Man]

I do, and they've been correctly adjusted.

Fronts require no adjustment by nature of the drop spindles. Rears have been adjusted so that just after staring the vehicle the compressor kicks on for just a second and raises the rear maybe a 1/4 of an inch.

Perfect.

 

[Hi-psi]

Doing a little more digging and seeing some discussion about the steering position sensor. One thing I forgot about is since the lowering kit install, not every time, but maybe 2-3 times when starting the vehicle for a moment it will say Stabilitrak Off in the DIC. I'm not getting any of the other typical messages tied to the steering position sensor (Traction Control Off, Service Stabiltrak, Service Traction Control) or any codes.

Although I only did one spindle at a time when lowing it, so there shouldn't have been any possibility of the steering wheel loosely rotating.

 

[Rocket Man]

Changed trans fluid last night, just dropped the pan and replaced filter. What a ***** that back left bolt is. Also replaced all the aged and cracking wire loom.

I hate that bolt. It’s the same on the NBS. There always has to be that one.

 

[Leo1103]

Been eyeing a set of power running boards, anyone ever swap a set from an esky to a tahoe (both nnbs)?