General Tech Help Good at troubleshooting? Have a non specific issue? Discuss general tech topics here.

service 4 wheel drive light

Old 09-10-2006, 06:36 PM
Beginning Member
Thread Starter
Join Date: Sep 2006
Posts: 20
gserve is an unknown quantity at this point
Default service 4 wheel drive light

Hi, I have a 2000 Blazer with the electronic 4 button 4X4 transfer case. I am having an issue with the service 4 wheel drive light coming on. This was coming on intermittently.Note that I was not trying to shift the transfer case at all. I did try to shift it and everything worked I was able to shift to 4 hi,4 lo auto 4 wheel and neutral. Now the problem is worse and all 4 lights on the switch stay on(even with the engine not running). I'm thinking its the TCCM (transfer case control module) Can someone tell me how to remove the kick panel to access the TCCM? Also if anybody has any other ideas or experience with this problem please let me know. Thanks
Old 09-10-2006, 11:18 PM
Junior Member
Join Date: Apr 2006
Posts: 467
RonJon is an unknown quantity at this point
Default RE: service 4 wheel drive light

I don't have any experience with your problem. That being said... now that all 4 lights are lit can you still shift ranges? If so I think your problem is probably in the control switch in the dash. The way things should work is the indicator LEDS are fed power (+) through the switch logic by a fuse that is only on in the run position of the key switch. Return (-) is controlled by the control module turning on that appropriate light. It's possible (on my 2000 at least) to carefully pry the switch out of the dash starting at the top, start with a screwdriver and use your fingernails so you don't scatch the dash (held in by plastic tabs). Remove the two electrical connectors. Using a test light with a self contined battery or a multimeter set to continuity check or ohms - one side connected to ground - key in run position - on the 8 wire connector check to purple/white (4LO lamp), tan/black (4HI lamp), , pink (Auto 4WD lamp) (careful now there's 2 light green/black wires, the one you want is top row/right side with the connector facing you - tab facing up) light green/black (2HI lamp) and on the 4 wire connector the brown wire on the end of the connector (Neutral lamp) (FYI brown wire next to it is 12V from fuse panel) you shouldn't have continuity to ground on ALL of those, just the selected range which was probably 2HI. If you have continuity on 2 or more either the harness rubbed to ground or it's the control module. If that's the case I have no idea how to remove the kick panel without breaking it.
Added: Check the fuses, #15 in the instument panel does the LEDS in the buttons and ATC in the underhood fuse box (right side looking down at it) powers the TCCM. I don't know if there's a back feed if one is blown but.... hope for the easy solution.
Related Topics
Thread Starter
Last Post
General Chat
09-12-2012 12:33 PM
2nd Gen S-series (1995-2005) Tech
03-07-2012 04:52 PM
Steering, Suspension & Drivetrain
06-23-2010 06:57 PM
2nd Gen S-series (1995-2005) Tech
02-24-2010 08:20 PM
Steering, Suspension & Drivetrain
04-04-2008 10:12 PM

Thread Tools
Search this Thread
Quick Reply: service 4 wheel drive light

Featured Sponsors
Vendor Directory

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.