Bigger tires / 17” wheels / level kit / intermittent ABS, Trailer Brake, Steering Assist Reduced warnings

[RockyMountainAT4]

2021 1500 AT4 6.2 crew
Hi all

Having an issue that I’m curious to see if anyone would have some insight on.

I added a readylift 1.75 level kit, 305/70/17 and 17” wheels

Problem -
Within a day of leveling kit, wheels/tires install, I was and have been getting intermittent, but simultaneous warning lights for ABS, trailer brake and steering wheel assist.
I could dismiss each warning with the steering wheel. I did that for a couple weeks but now (the latest development as of today) the warnings won’t dismiss using the steering wheel controls.
I can’t access driver information center whatsoever due to warnings not clearing.

Occasionally, the truck is great for a few days and it’s good. Occasionally, I’ll start the truck with foot on the brake and warnings appear, that now can’t be cleared.

What I’ve done so far -
-unhooked battery for a few hours
-used a friends new snap-on diag computer that shows no codes
-brake fluid seemed a bit low so I topped with dot4 fluid
-drove the truck 30-40 miles hoping a relearn / reset would take place

All connections appear to be solid and nothing seems out of place with the exception of the right front speed sensor wiring being a bit tight at full lock (no visible evidence of damage anywhere). I replaced that part with a new OE wheel speed sensor.
The problem remains.

I have a 14 hour drive tomorrow and was very hopeful a new speed sensor would correct this.
Thoughts anyone?
Thank you for any help
Shane

 

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[gemarsh]

 

[gemarsh]

You could have very well disturbed this ground while installing lift.

 

[RockyMountainAT4]

You could have very well disturbed this ground while installing lift.

Best info I’ve gotten yet. Great job on that find. Def gonna be looking at ground wires.
Thank you for taking time to help on this.

 

[kobra357]

You didn’t add a pulsar LT or pedal commander by chance?

 

[RockyMountainAT4]

You didn’t add a pulsar LT or pedal commander by chance?

I do not. Nothing of the sort.

 

[kobra357]

My pulsar caused all those codes and more. I had to return 2 different units, In the end Im going with deoblew or HP tuners now. Only reason I ask. I agree a ground is a really good place to start. Good luck.

 

[RockyMountainAT4]

GM dealer called today. They are saying that the BRAKE FLUID LEVEL SENSOR is the problem.
I guess it’s possible that the brake line / caliper pulled downwards harder than it should have been. I feel confident I handled it carefully - suspended / supported during install etc. but I guess not careful enough.
<$200
Fingers crossed this fixes it - esp for $200.
1000+ mile trip last week with no cruise is not fun.

 

[kobra357]

I agree thats odd. And maybe a coincidence? But anything’s is possible. Hopefully it’s that simple.

 

[gemarsh]

I don't believe if you had hung the calipers by their hose in the middle of an earthquake, it wouldn't had pulled on the fliud level sensor on the master cylinder.

I just think it failed by coincidence. Don't believe it's your fault at all.

 

[RockyMountainAT4]

I don't believe if you had hung the calipers by their hose in the middle of an earthquake, it wouldn't had pulled on the fliud level sensor on the master cylinder.

I just think it failed by coincidence. Don't believe it's your fault at all.

Thank you sir.
I’m very happy that fixed it.

 

[RockyMountainAT4]

Thanks fellas for all the suggestions and input. Brake fluid level sensor was the culprit and did fix the truck. $50 sensor, 10min to replace.