Replaced all elects on 4/4 no codes will not lock all the way into 4/4
2003 Chevrolet Tahoe

Replaced all elects on 4/4 no codes will not lock all the way into 4/4

(2003 Chevrolet Tahoe)
Actuator.control module encoder transfer case rebuilt can hear encoder working there is some movement on front wheels when locked in 4/4 high but will not spin on snow In auto you can turn front wheels by Hanson houst PS all work was done by GM CERT H/d people at a G/m shop Once again ALL ELECT PARTS HAVE BEEN REPLACEED Ithink I need a wiring cart to look for voltage loss NO CODES!!
1 answer & 7 comments
Popular Answer
on January 12, 2015
First thing to do is this simple test.... Find a dry, paved parking lot.... Put T-Case in 4 high.... While driving slowly, turn and 'hold' steering wheel hard right OR left.. Feel the vehicle bind up or buck as if the brakes were being applied and slowly released?.. Do you feel that??.. That's ALL I need to know for more info!
Sign in to reply
on January 14, 2015
Thank you Pushrod for your answer. I am having my girlfriend type the reply info as I am not able to find my sign in for this site.
We have tried locking it up in 4 wheel drive...wheels full right and full left to test for drive line bind up. There is none. There is not enough transfer case clutch pressure to spin front wheels on ice. GM tech is telling me the actuator is somehow losing it's home position.
Question: How much break away torque does the transfer case have in two wheel compared to 4 wheel auto? And 4 wheel High? We are able to turn front and rear drive shafts easily in all positions. We have No speed sensor codes or 4 wheel drive codes. Can codes be retrieved from module without TEC-2 scanner. HELP!!!
Thank you so much for any help that you may be able to give!!
on January 14, 2015
Any good scanner will work for testing.... Also IF you can hear the T-case shift, raise it on a lift and see if front driveshaft is turning... Have seen the plastic silencer pads break off shift fork inside T-case and not complete the shift sequence... This is all just some info that may or may not help..
on January 14, 2015
If truck is on lift Shafts will turn and having key on when you Putin 2wheel to auto or 4 hi You can hear ENCODER MORTOR WORKING THE ACTUATOR ON FRONT DIFF IS LOCKING IN FRONT DIFF. This transfer case has been apart and checked the part that is turned by Encoder inside the case has all so been changed thinking was it may be the problem Can the encoder forget and not move all the way into the right place Please remember All of the elect. Parts have been replace more them 3times thanks again any help is a new road for me to look at...
on January 14, 2015
IF the FRONT driveshaft is not turning in 2WD but IS turning when shifted into 4x4...and front wheels are not rotating... Then the problem has got to be in the front axle!!!... That's all there is to it!!!.. All the transfer case can do is spin the front shaft when shifted into 4WD... Front axle actuator has to engage axles... On a lift...shift into 4x4 trans in park...raise vehicle.. Now you and a helper try to turn BOTH front wheels in the same direction at the same time!!.. IF they turn, look to see if front driveshaft is turning as well ....post those results.
on January 15, 2015
I did do that, and there is movement on the front shaft on the lift in 2 wheel but it can be stopped by hand and in auto 4. If you grab both front wheels you can stop them easily then you put it in 4 HI vary little change. We went as far as to put on a torque meter the difference is vary little and the transfer case is not locking up. You can hear encoder working and it does add more torque on shafts from 2 wheel 4hi but not enough. Question: Does the senor in the encoder stop at the same place every time Or does it just go where it thinks it should go? Is there a way of finding out how or where it is and can this be changed? And if the encoder loses home what can we do to tell it where to go? BACK TO THE PARK ON LIFT IN 4 HI IN PARK BOTH SHAFTS CANT BE TURNED THEY BOTH LOCK UP THANKS AGAIN FOR YOUR HELP
on January 15, 2015
Ok.. You can stop both front wheels from turning when it is in 4x4, I got that, BUT.. Does the front driveshaft stop turning at that same time as well???... If it stops turning, your problem is transfer case related!... If the front driveshaft is still turning while BOTH front wheels are not.. Your problem is in the front axle.. FRONT DIFFERENTIAL ACTUATOR is NOT engaging the front axle shafts PROPERLY!!! The encoder motor is like a switch.. On or off every time, according to slected mode!.. So I guess what I want to know IS > can you stop the front DRIVESHAFT from turning with any 4x4 range selected BUT the rear wheels are still turning??? I am pretty your problem is in the front axle!!
on January 15, 2015
Front drive shaft turns with front diff. Front diff is locked in. Pressure on transfer case clutch pac, must be the problem. How do you check movement of the encoder? Can the encoder be removed from the transfer case in 4 hi and still stay in that position? I was told if the encoder is removed, the case will go back into neutral position. Tech 2 scanner shows actuator on and encoder motor in 4 HI, but still not enough pressure to turn tires on bare ice. How can we determine position on the encoder to make sure it is engaging clutch pac all the way? Question: The position sensor in the encoder tells encoder how far to move? OR is it controlled by the farther it pushes on the clutch pac, the more power/electric it uses? And is it possible that if there is a loss of power at anytime, will the encoder lose it's home or position status?
Okay.....back to you. After dealing with this for so long and talking to rebuilders GM techs, one tells me the ecm on board does not control any 4 wheel drive issues. Others have said to check connections at ecm under counsel cup holder for corrosion. (I am willing to do this) But I have tried to get a wire schematic so that I could be a bit more certain of which way to go and this has been a hunt that I have not accomplished. Again, thanks for hanging with me on this.
General Diagnosis
$88 - $111 Learn More
on January 12, 2015
First thing to do is this simple test.... Find a dry, paved parking lot.... Put T-Case in 4 high.... While driving slowly, turn and 'hold' steering wheel hard right OR left.. Feel the vehicle bind up or buck as if the brakes were being applied and slowly released?.. Do you feel that??.. That's ALL I need to know for more info!
Sign in to reply
on January 14, 2015
Thank you Pushrod for your answer. I am having my girlfriend type the reply info as I am not able to find my sign in for this site.
We have tried locking it up in 4 wheel drive...wheels full right and full left to test for drive line bind up. There is none. There is not enough transfer case clutch pressure to spin front wheels on ice. GM tech is telling me the actuator is somehow losing it's home position.
Question: How much break away torque does the transfer case have in two wheel compared to 4 wheel auto? And 4 wheel High? We are able to turn front and rear drive shafts easily in all positions. We have No speed sensor codes or 4 wheel drive codes. Can codes be retrieved from module without TEC-2 scanner. HELP!!!
Thank you so much for any help that you may be able to give!!
on January 14, 2015
Any good scanner will work for testing.... Also IF you can hear the T-case shift, raise it on a lift and see if front driveshaft is turning... Have seen the plastic silencer pads break off shift fork inside T-case and not complete the shift sequence... This is all just some info that may or may not help..
on January 14, 2015
If truck is on lift Shafts will turn and having key on when you Putin 2wheel to auto or 4 hi You can hear ENCODER MORTOR WORKING THE ACTUATOR ON FRONT DIFF IS LOCKING IN FRONT DIFF. This transfer case has been apart and checked the part that is turned by Encoder inside the case has all so been changed thinking was it may be the problem Can the encoder forget and not move all the way into the right place Please remember All of the elect. Parts have been replace more them 3times thanks again any help is a new road for me to look at...
on January 14, 2015
IF the FRONT driveshaft is not turning in 2WD but IS turning when shifted into 4x4...and front wheels are not rotating... Then the problem has got to be in the front axle!!!... That's all there is to it!!!.. All the transfer case can do is spin the front shaft when shifted into 4WD... Front axle actuator has to engage axles... On a lift...shift into 4x4 trans in park...raise vehicle.. Now you and a helper try to turn BOTH front wheels in the same direction at the same time!!.. IF they turn, look to see if front driveshaft is turning as well ....post those results.
on January 15, 2015
I did do that, and there is movement on the front shaft on the lift in 2 wheel but it can be stopped by hand and in auto 4. If you grab both front wheels you can stop them easily then you put it in 4 HI vary little change. We went as far as to put on a torque meter the difference is vary little and the transfer case is not locking up. You can hear encoder working and it does add more torque on shafts from 2 wheel 4hi but not enough. Question: Does the senor in the encoder stop at the same place every time Or does it just go where it thinks it should go? Is there a way of finding out how or where it is and can this be changed? And if the encoder loses home what can we do to tell it where to go? BACK TO THE PARK ON LIFT IN 4 HI IN PARK BOTH SHAFTS CANT BE TURNED THEY BOTH LOCK UP THANKS AGAIN FOR YOUR HELP
on January 15, 2015
Ok.. You can stop both front wheels from turning when it is in 4x4, I got that, BUT.. Does the front driveshaft stop turning at that same time as well???... If it stops turning, your problem is transfer case related!... If the front driveshaft is still turning while BOTH front wheels are not.. Your problem is in the front axle.. FRONT DIFFERENTIAL ACTUATOR is NOT engaging the front axle shafts PROPERLY!!! The encoder motor is like a switch.. On or off every time, according to slected mode!.. So I guess what I want to know IS > can you stop the front DRIVESHAFT from turning with any 4x4 range selected BUT the rear wheels are still turning??? I am pretty your problem is in the front axle!!
on January 15, 2015
Front drive shaft turns with front diff. Front diff is locked in. Pressure on transfer case clutch pac, must be the problem. How do you check movement of the encoder? Can the encoder be removed from the transfer case in 4 hi and still stay in that position? I was told if the encoder is removed, the case will go back into neutral position. Tech 2 scanner shows actuator on and encoder motor in 4 HI, but still not enough pressure to turn tires on bare ice. How can we determine position on the encoder to make sure it is engaging clutch pac all the way? Question: The position sensor in the encoder tells encoder how far to move? OR is it controlled by the farther it pushes on the clutch pac, the more power/electric it uses? And is it possible that if there is a loss of power at anytime, will the encoder lose it's home or position status?
Okay.....back to you. After dealing with this for so long and talking to rebuilders GM techs, one tells me the ecm on board does not control any 4 wheel drive issues. Others have said to check connections at ecm under counsel cup holder for corrosion. (I am willing to do this) But I have tried to get a wire schematic so that I could be a bit more certain of which way to go and this has been a hunt that I have not accomplished. Again, thanks for hanging with me on this.

Similar Questions

View answers to similar questions from RepairPal's community of auto experts and enthusiasts.
I own a 2004 chevy tahoe 2wd and my 4l60e was just fully rebuilt. once installed all gears shift perfectly however...
After stuck in snow loss of steering power