97 Yukon won't shift right when ABS light is on

[RGreen]

I've had a couple of incidents where the ABS light comes on on the dash, and then the transmission won't shift properly. It happens on cold, wet days. I've been told that this vehicle (97 GMC Yukon 4WD 5.7) does not have interface between the transmission and the braking system, yet it's happening. Anyone have any ideas, questions, or things I can check? The only codes the transmission shop said they found were C0036 and C0037, but of course it did not give them any problems when they drove it.

 

[exp500]

Those are wheel speed sensor codes for front. Has any work been done to the wheel areas around the time the codes began? You can try replugging the sensors, and if you are over 125k miles you are a candidate for new hub bearings and sensors anyway.

 

[Bill 1960]

Are you seeing any loss of power when the light comes on, as if the ABS system thinks it’s really losing traction?

 

[scotto0609]

Is there a common ground between the two systems?

 

[exp500]

If he is in 4auto could be his issue. If he has NP-246, 2wd should only be a nuisance light.
Grounds are a problem on ANY vehicle. Worse in rust belt.

 

[RGreen]

If he is in 4auto could be his issue. If he has NP-246, 2wd should only be a nuisance light.
Grounds are a problem on ANY vehicle. Worse in rust belt.

I was able to drive it home by manually shifting from low gear to drive. Didn't seem to have any problems when I did it that way.

 

[RGreen]

Those are wheel speed sensor codes for front. Has any work been done to the wheel areas around the time the codes began? You can try replugging the sensors, and if you are over 125k miles you are a candidate for new hub bearings and sensors anyway.

Haven't had any work done in the front. I bought this as a used high mileage fixer upper. You're not the first to suggest the hubs.

 

[exp500]

RGreen- post a pic of your RPO codes from glove compartment. Or look at Tcase see if it is NP246.
And unplug/ clean /replug near frame/upper control arm. Clear codes, see if it comes back.
It is about 3 hour job to change both sides, Check ball joints and axles first, because if you are that far apart and it needs them, do it then.

 

[RGreen]

I have a

RGreen- post a pic of your RPO codes from glove compartment. Or look at Tcase see if it is NP246.
And unplug/ clean /replug near frame/upper control arm. Clear codes, see if it comes back.
It is about 3 hour job to change both sides, Check ball joints and axles first, because if you are that far apart and it needs them, do it then.

I have the 272 transfer case.

 

[RGreen]

No lo

Are you seeing any loss of power when the light comes on, as if the ABS system thinks it’s really losing traction?

No loss of power. Whatever is happening it is making it not engage the torque converter lock up. Almost as if it is slipping.