2003 Chevrolet Blazer Sunroof By-Passing the Closed Position

Tiny
LAWGIVER
  • MEMBER
  • 2003 CHEVROLET BLAZER
  • 4.3L
  • V6
  • 4WD
  • AUTOMATIC
  • 45,000 MILES
Hello Everyone,

Just purchased a 03 ZR2 Blazer. I noticed the sunroof is not stopping in the closed position. I searched through the owners manual and could not find one reference to sunroof operation but managed to find some info online. If I push and release the toggle switch to the rear, the roof opens and stops at the halfway position. Will not open all the way. If I push and hold the toggle in the forward position the sunroof will open to the vent position. If I push the toggle to the rear to close the sunroof, the roof will again open to the halfway position. I obviously have an issue going on. The sunroof is not stopping in the closed position at all or opening all the way. Motor sounds good, no clicking and/or binding. Sunroof slides w/out issue. Tracks look fine and nothing appears to be broken. In searching the net, I have found posts concerning re-calibration of the sunroof module and drive motor timing. I don't know how correct this info is. Also found a reference to a GM# 12333707 sunroof module as being faulty. Can these modules be tested at all? Any assistance would be greatly appreciated. Thank you all for your time.

Regards,
Rob
Do you
have the same problem?
Yes
No
Thursday, November 19th, 2015 AT 9:58 PM

10 Replies

Tiny
HMAC300
  • EXPERT
Yes they can be tested but yo need a pro with a scanner to do it. You can try this first as far as timing goes. Yo have to remove the headliner too.
Was this
answer
helpful?
Yes
No
Friday, November 20th, 2015 AT 7:32 AM
Tiny
LAWGIVER
  • MEMBER
Hello,

Thank you for the response. I attempted that timing procedure last night before posting my question. Did not have a lot of luck with that. After moving the roof back by hand to the full open position, I re-installed the motor. Pushed the toggle switch forward and the window only closed halfway. Pushing the switch forward again does nothing. Pushing the toggle switch to the rear, the window opens full again. Pushing the switch again to the rear results in the motor clicking/grinding. I removed the motor again and moved the roof as far forward as I could get it. Re-installed the motor and thankfully right back to where I started and could get the window to sit flush with the roof line by moving the toggle switch back and forth.

Rob
Was this
answer
helpful?
Yes
No
Friday, November 20th, 2015 AT 12:13 PM
Tiny
HMAC300
  • EXPERT
Once you do what you did you have to move it several times not just once. If it's not fixed then check for broken parts like a cable etc.
Was this
answer
helpful?
Yes
No
Friday, November 20th, 2015 AT 1:02 PM
Tiny
LAWGIVER
  • MEMBER
Well, that I did not do. I attempted to move the roof forward twice with the switch and both times it would close halfway and stop. After that I reset everything to the way it was before. Why does it have to be moved several times? Does the module re-learn the roof positions? My only concern with trying that procedure is the clicking/grinding of the motor. I am assuming I don't have to take it that far. Just close and back from the full open position once the glass is reset back to the roof line?

As far as the tracks and cables, everything looked good. I did not see anything broken. The glass has no problem sliding back and forth and going to the vent position at all. All sounds normal when the glass is in motion. Thanks again for your time.

Rob
Was this
answer
helpful?
Yes
No
-1
Friday, November 20th, 2015 AT 5:22 PM
Tiny
HMAC300
  • EXPERT
It has to do that so it will see if there are problems or not. You might want a local guy to scan this for codes as the motor should not grind or click as that makes me think there is another problem that you can't see. Take the motor out and see if the cables are messed up there then slide glass back a tad and see if they look the same I really think that is your problem. Usually when this stuff happens it's because of a cable problems against the motor gear. It should not make that noise.
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 6:40 AM
Tiny
LAWGIVER
  • MEMBER
The only time the motor clicked/grinded was after I readjusted the glass to the rear of the sunroof opening following the timing procedure. Once the glass was at the rear, I re-installed the motor. Hitting the forward button, the glass would move forward and stop halfway. Hitting the rearward toggle, the glass would slide back to the full open position and stop. Hitting the rear button again would cause the grinding or clicking of the motor. Now I realize that is normal to hear the clicking if the glass is hitting the stops and the motor tries to move it back further. But, since I don't know how this thing is supposed to work correctly to begin with, I don't know if that is "normal" to begin with. If I put everything back the way it was originally, the motor is quiet and makes no noise. When the glass is in the vent position, you can push the forward toggle and hear the motor power up but it does not click/grind. That operation seems "normal" to me. The motor seems aware that the glass is in vent and can go no further and does not try and move it. It is the same for the rearward toggle. The glass will slide back halfway and stop. If you push and hold the switch again, you hear the motor power up but it does not try and move the glass. Now I am "assuming" that is how the whole set up is supposed to work. You can push and hold those buttons all day once the glass reaches the end of travel and the motor will not engage and damage itself. It just seems my glass doesn't have a clue where it's at other than the vent position. If you think I should make another attempt, I can try the timing procedure again and this time move the glass back and forth several times as suggested. As long as I don't push the rear toggle again when the glass in in the full back position, I won't cause the motor to grind.

As far as the cables, I did stick my head through the roof when I had the glass all the way back. Other than needing some grease, it looks normal to me. I can slide the glass forward and backwards w/out a problem, cables look the same for both sides.

I apologize for the length of the post. I realize it's difficult to diagnose a problem w/out actually looking at it. I wanted to provide as much info as I could. Thank you for your time.

Rob
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 11:55 AM
Tiny
HMAC300
  • EXPERT
I really thin k you should have this scanned for codes there may be a limit switch that is causing all this stuff to happen. The motor connects to the module by a driveshaft and the limit switchs are in the module. But you can only read this with a scanner and that may be what's wrong, nothing mechanically. Any garage with a pro scanner can read this.
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 12:07 PM
Tiny
LAWGIVER
  • MEMBER
That's interesting. If I am understanding correctly, there are limit switches in the motor itself? I was under the impression that the sunroof module controlled the functions of the roof and all the motor did was drive the unit. I did find another module (GM 12533707) at my local yard and plugged that into the system. Didn't make a bit of difference. The roof behaved that same with either module.
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 12:35 PM
Tiny
HMAC300
  • EXPERT
No there is a motor and a module to run the sunroof I can't help you any further so your best bet is to get it scanned see if they come up with anything.
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 3:34 PM
Tiny
LAWGIVER
  • MEMBER
OK, I just wanted to make sure I wasn't missing another piece of the puzzle so to speak. I was under the impression the motor was just a "motor" and had no other control functions other than moving the glass back and forth. I will take it into the dealer. I really appreciate your assistance. Yours was the most help I received out of all my forum posts and such. I am grateful for your time. Take care and have a Happy Thanksgiving.

Rob
Was this
answer
helpful?
Yes
No
Saturday, November 21st, 2015 AT 9:02 PM

Please login or register to post a reply.

Recommended Guides