2005 Tahoe LT Autoride Traction Control

[pumpkin_hook]

I have a 2005 Tahoe LT w/autoride, AWD. The issue is the traction control activating primarily when moving from a stop. This is what I have done so far:

2020: replaced front wheel sensors (ACDELCO 84356645); replaced wheel hub (SKF BR930304, no sensors incl.)

This setup worked for ~18mo. Starting in the fall of '21, when moving from a stop, the traction control activated; if you let off gas momentarily, the TC stopped and normal driving resumed until another stop. I got into the habit of disabling TC upon initial start (before moving).

2022 - I recently replace the sensors again (ACDELCO 84356645) but the condition worsened - the TC was always active, so I returned to the old sensors. I purchased a different sensor (GM 15233108) that seemed to be the correct part for AWD Tahoe's . This time the TC activated when moving from stop as well as when stopping.

None of the replacement sensors included shims. How can one tell if the shims are needed to correctly set the gap to the sensor ring - meter, 'scope, OBDII scan tool, other? Where can shims be purchased?

Are my conditions indicative that the ABS module needs to be replaced? From my research, the AWD version requires a different module than the 4WD version.

Thank you for any assistance.

 

[wjburken]

Do you have a scan tool that can read ABS codes? That might help you zero in on what the issue truly is.

 

[S33k3r]

Check your grounds. The one just under the driver's door sill is notorious for problems like this. And checking them all is just a good idea anyway.

I'd also check your alternator output. Small systems breaking down like this can be an alternator going as well.

 

[pumpkin_hook]

Thank for both replies. I will be looking into both today.

 

[MassHoe04]

Tech 2 scan tool will get you deep into every possible component and will save big bucks.

Before I got my Tech 2, I found out my Zurich scan tool from Harbor Freight was able to get into ABS through a special sub-menu called "General Motors OEM Enhanced" or "GM OEM Enhanced" ( I can't recall exactly).

That was where multiple ABS codes were kept. None of the codes would cause a DTC code to trip, or basic san would show no DTCs stored.

That OEM Enhanced menu is where I found a C0035 code. That pointed directly to issue with the left front ABS speed sensor.

I think that Zurich will also allow you to look at ABS speed sensor output on live data, which can be really helpful. Sensors need to be sending output within a specific range of values. Too close to the tone ring or too far, can definitely impact what the sensor is send back to the control module.

Tech 2 tool is about $300 and worth much more than that in time and money saved.
If you have or can get a Zurich (the one that sells for about $100 and has ABS servicing capabilities, something like that might get you where you need to go with this ABS diagnosis.

 

[rockola1971]

Check hubs for excessive play. Jack front wheels off the ground and rock wheel at 9 and 3 oclock position. You will feel it if hubs are bad. Bad hubs will cause inaccurate wheel speed to be reported and will cause funky problems if only one hub is intermittently causing a bad signal output.

 

[VR4Play]

Sounds like the air gap on the sensor is incorrect. Take some sandpaper and sand where the sensor goes in to the bearing so that it is nice and clean. If you have a scan tool and can see live data look at all the sensors and see which one drops input or does something strange. Could be a rear wheel speed sensor if it's activating traction control.

 

[rockola1971]

Sounds like the air gap on the sensor is incorrect. Take some sandpaper and sand where the sensor goes in to the bearing so that it is nice and clean. If you have a scan tool and can see live data look at all the sensors and see which one drops input or does something strange. Could be a rear wheel speed sensor if it's activating traction control.

Exactly and a bad hub will cause the air gap to change between the ABS sensor and its metal target which yields signal drop out or erratic signal values.

 

[Doubeleive]

Looking at ABS live data (4 channel) will point you to the source

 

[Matahoe]

Had to sand my axle as well. There was tons of rust on the rear left and right axle tubes. Pretty obvious that putting new sensors in place with no rust removal would make the air gap bigger. In effect would make the problem worse not better.