97 Suburban - transfer case will not shift

Vehicle is 97 Suburban 1/2 ton 4x4 with 350 Vortec. 200,000 miles and tranny rebuilt at 115,000

For about the last 4-5 months, my transfer case selector switch does not light up and no shifting occurs with any button depressed (luckily, vehicle is at least in 2HI). Replaced the switch as I found one cheap - no change. When key turned to ON, the 2HI light comes on and then goes out a couple of seconds later. After that, no lights or anything. I found this thread tonight (http://www.automotiveforums.com/vbulletin/showthread.php?t=725584)

I tried the fuse replacement and no help for me unfortunately. I have been worried that is it coming down to the transfer case drive motor, but hoping it might still be something less costly. Any ideas on what else I can check?

Thank you,
Shane

Vehicle is 97 Suburban 1/2 ton 4x4 with 350 Vortec. 200,000 miles and tranny rebuilt at 115,000

For about the last 4-5 months, my transfer case selector switch does not light up and no shifting occurs with any button depressed (luckily, vehicle is at least in 2HI). Replaced the switch as I found one cheap - no change. When key turned to ON, the 2HI light comes on and then goes out a couple of seconds later. After that, no lights or anything. I found this thread tonight (http://www.automotiveforums.com/vbulletin/showthread.php?t=725584)

I tried the fuse replacement and no help for me unfortunately. I have been worried that is it coming down to the transfer case drive motor, but hoping it might still be something less costly. Any ideas on what else I can check?

Thank you,
Shane


I don't know for sure on a 1997 , but on the 1999 on up when this occurs and at your mileage this usually means at the minimun a bad encoder motor...ya it could be wires shorted and all of that in addition to the motor..

If you get DTC I can give you better facts..on what it is..

I don't know for sure on a 1997 , but on the 1999 on up when this occurs and at your mileage this usually means at the minimun a bad encoder motor...ya it could be wires shorted and all of that in addition to the motor..

If you get DTC I can give you better facts..on what it is..

What is DTC and how do I get it?

What is DTC and how do I get it?


a oem dealer can pull these as well as any repair shop that has a scanner that can read these manufacturer specific codes for the drive train. call and ask first if they can and how much to pull this code info..

Shane:

DTC=Diagnostic Trouble Code and as stated only a scan tool that can access the Transfer Case Control Module will pull the codes. Over the counter code readers do not have that capability.

By the way, how many buttons are on your T-Case switch panel and how are they labeled?

The most likely cause is the t-case motor, but without the DTC's it would be a shot in the dark.

Shane:

DTC=Diagnostic Trouble Code and as stated only a scan tool that can access the Transfer Case Control Module will pull the codes. Over the counter code readers do not have that capability.

By the way, how many buttons are on your T-Case switch panel and how are they labeled?

The most likely cause is the t-case motor, but without the DTC's it would be a shot in the dark.

On my switch panel, there are 3 buttons: 2HI, 4HI, and 4LO.

Yesterday, after having the battery disconnected for some other work, I hooked everything back up an turned the key on and all 3 switch panel lights came on for a few seconds and then turned off.

No secret handshake McGuyver method of checking the codes eh... I guess I will see if I can find a sho; to help me out. Most around here charge $70 just to hook up the scan tool.

On my switch panel, there are 3 buttons: 2HI, 4HI, and 4LO.

Yesterday, after having the battery disconnected for some other work, I hooked everything back up an turned the key on and all 3 switch panel lights came on for a few seconds and then turned off.

No secret handshake McGuyver method of checking the codes eh... I guess I will see if I can find a sho; to help me out. Most around here charge $70 just to hook up the scan tool.

Here is a 70$ tip on gettingn codes.

To get codes on that one ground pin 13 on diagnostic connect and count the shift button blinks.

The only have codes 1-4.
Post back code no.

On my switch panel, there are 3 buttons: 2HI, 4HI, and 4LO.

Yesterday, after having the battery disconnected for some other work, I hooked everything back up an turned the key on and all 3 switch panel lights came on for a few seconds and then turned off.

No secret handshake McGuyver method of checking the codes eh... I guess I will see if I can find a sho; to help me out. Most around here charge $70 just to hook up the scan tool.


this cost of code reading WILL be the least expensive part of the repair...knowing the problem area is best known before repairs/parts are started.

If you have good mechanical skills this job is not very difficult..also there are motors available on line for a much lower price than the dealer...

Thanks guys. I was just thinking I had read somewhere before that these codes could be checked somehow without the scanner, like MT brought up. My only question though is for verification: when you say ground pin 13, you are talking about where the OBD scanner hooks up, or somewhere else?

Thanks again for the help. If I am going to have to replace the motor, I would rather put the $70 towards that if possible.

Thanks guys. I was just thinking I had read somewhere before that these codes could be checked somehow without the scanner, like MT brought up. My only question though is for verification: when you say ground pin 13, you are talking about where the OBD scanner hooks up, or somewhere else?

Thanks again for the help. If I am going to have to replace the motor, I would rather put the $70 towards that if possible.

Pin 13 in link below.
http://www.troublecodes.net/OBD2/

Ground it and flip key on and count blinks and save 70$
Post back code.
Good luck

All 3 button lights should blik together
If no codes button lights will blink one time and quit.

If code the shift buttons will blink code and the after a 3 second pause blink the code or codes again and again.

All 3 button lights should blik together
If no codes button lights will blink one time and quit.

If code the shift buttons will blink code and the after a 3 second pause blink the code or codes again and again.

I made an assumption off the link you sent me that I could ground pin 13 to pin 4 (chassis ground). Assuming that is good assumption, it appears I am getting no codes. All 3 lights came on, stayed on for maybe 3 seconds, and then go off and stay off. Did I make the correct assumption on the ground pin?

I made an assumption off the link you sent me that I could ground pin 13 to pin 4 (chassis ground). Assuming that is good assumption, it appears I am getting no codes. All 3 lights came on, stayed on for maybe 3 seconds, and then go off and stay off. Did I make the correct assumption on the ground pin?


Yes
Sounds like no Codes.
Back to the drawing board.
Good Luck

Yes
Sounds like no Codes.
Back to the drawing board.
Good Luck

if no codes, could it still be the motor? Does the fact that there are no codes tell me anything good about this situation?:lol2:

Very well could the motor or maybe be.
But could be wiring or shift buttons or power or ground problem.
But with no codes.
To be sure you need to do some proper testing.
A good factory service manual or a All data online sub will take you threw the proper test.
26.95$ US plastic and 10 minutes and you will be set to go on testing with a one year one car online sub setup.
http://www.alldata.com/products/diy/index.html

To be for sure run the test as outined in service manual.
Good Luck

Looks like I will be purchasing the alldata deal. Once I have it, is there a section or area I should look at specifically for my problem. Just wondering what to expect from it.

Thanks

looks like I will be getting the alldata sub. Once I have it though, is there a particular area if it I should go to look at more info on my problem? Just wondering what to expect from it... thanks!

Go to powertrain/transfer case repair and testing info.
You may have to look around a little but.
It should all be in there.
Good Luck

Go to powertrain/transfer case repair and testing info.
You may have to look around a little but.
It should all be in there.
Good Luck

Yeah, looking around now.

Is there an easy way to test the TCCM?

OK, another question...

I am confused about the actual locatino of the TCCM. One diagram on the alldata site showed it behind the instrument cluster somewhere. Another thing I looked at made it sound like it is behind the pax side kick panel. Does anyone know the rigth location. I want to make sure I have a good connection to it.

OK, I have a new update...

Apparently, you cannot use the pin 4 for ground. Does not make sense to me being that is is a chassis ground, but I looked at everythign again and saw that pin 5 was a signal ground. I decided to try pin 13 grounded to pin 5. I have the 2 flash code doing it this way. Does this mean the drive motor is bad? I looked through some troubleshooting stuff on alldata, but afraid the part about the codes is more confusing at this point as they list A codes, B codes, and C codes. I guess you have to have the right scanner for that to be of help. Is what I am doing here definitive at all. Wife is supposed to leave Wednesday morning for South Dakota and I would feel better about her having 4wd for trip.

Thanks all.

if no codes, could it still be the motor? Does the fact that there are no codes tell me anything good about this situation?:lol2:


try this site :http://www.blazerforum.com/m_56175/tm.htm

This is out of my '98 C/K service manual.

DTC 2 = "During electronic shifting the TCCM checks the encoder/motor for normal operation. If the encoder/motor does not function correctly enough times the TCCM stores a motor/encoder failure DTC2".

Have you tried to shift the t-case to see what happens? It's possible you may have reset the electronics when you disconnected the Batt.

DLC pin 4 should have given you a good ground for the test. You may want to test that pin again for a good ground and we may have to address an issue with that!! Pin 5 is a ground source for the VCM.

Also need to look at the wiring connections at the motor.

Otherwise, sorry to say, you're looking at replacing the t-case encoder/motor.

OK, I have a new update...

Apparently, you cannot use the pin 4 for ground. Does not make sense to me being that is is a chassis ground, but I looked at everythign again and saw that pin 5 was a signal ground. I decided to try pin 13 grounded to pin 5. I have the 2 flash code doing it this way. Does this mean the drive motor is bad? I looked through some troubleshooting stuff on alldata, but afraid the part about the codes is more confusing at this point as they list A codes, B codes, and C codes. I guess you have to have the right scanner for that to be of help. Is what I am doing here definitive at all. Wife is supposed to leave Wednesday morning for South Dakota and I would feel better about her having 4wd for trip.

Thanks all.


dtc 2 usually means a shorted out encoder motor...this will also come up if the motor is open or if the motor is not moving as commanded.


obviously anytime an electrical device has issues wire/connectors must be inspected ...but you will be doing that any how..


now the search . the quest for the cheapest supplier....One hint:It won't be your local chevy dealer....