Mechanics

CHEVY 4WD

1996 Chevrolet Silverado

Transmission problem
1996 Chevy Silverado V8 Four Wheel Drive Automatic 200000 miles

4wd hi button only blinks, keeps blinking, wont go into 4wd. I can hear motor when I press button but front wheels dont engage. Instaled a new USED actuator same result. Is there a way to tell if this a tccm problem, fuse I dont know of (checked #24 4x4), transfer case, switch etc.?
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Donniesusan
January 4, 2009.




Ok we are going to pull codes to see what the codes may be present so we can see what it say's may be wrong with it. So the data link connector (DLC) is near the right side of the steering column. Now you need to make a jumper wire to go from the orange wire or term. number 13 at the DLC and ground. NOw turn key on engine off and watch the 4x4 light on the switch as it will flash codes to you. Now it will flash like a 1 pause 3 seconds and flash like a 3 meaning a 1 and a 3 as all transfer case DTC are single digit. So if you look at the diagram below it shows how it pauses as an example ok. After writing down all codes you will need to turn off the key and pull the 4x4 fuse and now turn the key on engine off 5 times this will clear all the codes from memory.
Now if you look at the graph below it shows what a code 2 will look like and what a code 1 and 3 will look like ok. Let me know what you find.


http://www.2carpros.com/forum/automotive_pictures/249564_Graphic_20.jpg


Racefan966
Jan 5, 2009.
OK. Used jumper to connect 13 to 5 (ground?). 2hi light went off when I did so. Turned key off. No code at all.
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Tiny
Donniesusan
Jan 5, 2009.
Ok did you do the reset procedure? If not do that just to see if it resets things. If nothing changes then we will have to test the stuff one item at a time.
Now we need to check voltages at TCCM harness (transfer case control module). With key on engine off you need to check for power at the following terminals. Refer to the diagram below ok. C8, C11, C12, C14, D14 and D15. Then check for resistance at C10 to ground it should be 2 ohms or less. If all it good then you will need to pull the 4x4 selector switch out and check for voltage at the pink wire at the switch. If all this is good then we will move to the next step. The diagram below will be needed for that too. Thanks and get back to me.


http://www.2carpros.com/forum/automotive_pictures/249564_Graphic_21.jpg


Racefan966
Jan 6, 2009.
I did the reset procedure, I got the 2hi button to blink a code one, with a barely visible light. Not sure if that counts. Also I do not know where the tccm is or what it looks like. So far Ive found a metal box near the steering column 4" x 4" x 2" approximately.

Tiny
Donniesusan
Jan 6, 2009.
It is under the dash on the steering column support bracket. If this checks out then we will check the transfer case relay. Let me know what you find ok. Thanks.

Racefan966
Jan 7, 2009.

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