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4WD Indicator Switch Light not Working

52K views 11 replies 7 participants last post by  SmithSteffin 
#1 ·
I have a 2002 TB and the 4WD Indicator Switch Light has stopped working. This is the 3rd time this has happened. Initially the Switch was replaced under warranty/recall in 2005'. Last December (2007) the light went out again and I had to replace the transfer case module. Now the light is out again? Can someone help me. I love the truck, but if Chevy can't solve the problem then I don't know what to do. Could it be something other than the Switch or Transfer Case Module? Also, whenever I get into the vehicle the "airbag" and "seatbelt" light stay illuminated. Eventually the seatbelt light goes off but the AB light continues to stay lit. Could these problems be related (4WD Indicator Light, AB and SB lights?)
 
#2 ·
As far as the 4wd switch. I only replaced mine once in my 2002 Trailblazer. I would try to disconnect the battery for 15 minutes and see if the switch starts to work. IF not I would get the truck checked to see if there is any stored codes in the PCM.


For the Airbag light, there are 2 sensors in the front bumper and 1 under each seat. I have heard that multiple drivers move the seat forward and backwards can cause the connector under the seats to become disconnected. I would get the PCM read for Errors and get them fixed ASAP.
 
#4 ·
my 2002 is doing the exact same thing, airbag light, seat belt light sometimes, and 4wd is not working.
i think it set a code of c0321 - set in transfer case
and a 99256 no abs communication and could not connect to airbag
or something like that as i was getting them from info from my wife.
 
#5 ·
My wife is at the dealership as we speak. When I got home she said the light was on again. Then later when she got back into the truck it went off again.
I did notice last December (after my dealer visit to try to solve the indicator light problem) that the vehicle made an odd "humming" noise when 4WD is engaged and I was on the highway traveling above 50 mph. I don't profess to know a lot about 4WD or cars in general, but maybe vehicles w a "4WD" setting aren't meant to be driven above a certain speed. The dealer has alredy said that there will be an additional $90 charge for the diagnostic (surprise!) even though it was in for the same problem in December. depending on whether it's the same codes will determine if they will honor their work. I'll bet that they come-up with a different problem other than the Module as before.
 
#6 ·
4WD switch status

Hi nike23, I'm just curious what the problem was with the 4wd not working. I am having the same exact problem as you where I have the same truck and the switch was replaced once by the dealer under warranty. Actually, I just called them and found out that they closed down with our crappy economy. I will try disconnecting the battery but don't have much faith it will work...

Thanks
Buzz
 
#7 ·
4WD Switch Status

Hello Buzzsawstanley,

Sorry to hear about your 4WD problems. Believe it or not but when my wife got to the dealership and the mechanic began to service the truck the light mysteriously came back on. Of course she was probably viewed as the typical female and not taken seriously. Since then it has not been back on but...the airbag and seatbelt light continue to stay on when the truck is started. We were told by a seperate mechanic (not GM) that this problem is the airbag sensor - why the airbag sensor somehow controls the seatbelt light remains a mystery. Someone replied earlier that the 4WD problem and the airbag and seatbelt sensor are all related so if you lights are on or come on in the future then I suspect that there is another problem GM has not properly diagnosed. I'm not sure how much this response has helped you but good luck in correcting your problem.
 
#8 · (Edited)
Same issue here, accidentally left the key switch on and drained the battery dead. After charging the battery the check engine light is on, the airbag light is on and the four wheel drive light is out and there is no 4wd. No codes where thrown. Unplugged the map sensor to get it to throw a engine code and cleared that which put out the check engine light only. Had the airbag reprogrammed at myairbags.com. Reinstalled module, and the airbag light is still on. Tried the battery disconnect, the #8 fuse and the #48 in rear fuse disconnect for 30 seconds and nothing put out the light. One thing I noticed is that the radio stations are not getting lost even when I disconnect both pos and neg from battery for an hour. That’s not normal. It’s a boose system, but I unhooked the battery before and lost the presets. Now they remain. Bought a new code reader with support for SRS and under enhanced srs dtc there is a b1000, ecu malfunction2 code. That could be thrown for many reasons. You can clear the b1000 but upon relink it’s back. If I disconnect any airbag sensor they throw a code that you can erase but upon relink they are back. If I connect the sensor back and relink code reader the code disappears. I don't know if the ECU (engine control module) and the TCCM (transfer case control module) lost their programming or if they need to be replaced. What is a person to do. If I take it in and they are junk I have to pay twice, because the ECU has to be programmed by VIN #.
 
#9 ·
Same exact problem

Has anyone concluded what the issue was??? I am have the exact same issue. Airbag/seat belt light and 4wd not working. No lights on the switch and no 4wd. Tried the wake up fuse trick...nothing happened. I replaced the switch and took a TCCM with same part numbers and tried that...nothing happened. I hooked it up to a snap-on scanner and it could communicate to the TCCM and the switch so we are pretty sure those are not the problems. Although the scanner was for only vehicles up to 2000 and mine's a 2003. What would be my next step? I was thinking about replacing the encoder motor and front actuator. Does anyone think that would help?
 
#10 ·
fixed my problem

I fixed the problems by replacing the transfer case control module located on drivers side middle of dash, can be seen from inspection cover behind front door in dash. And replaced the air bag module under rear of center console, tucked under carpet. Bought used ones from a 2004 on Ebay, didn't need reprogramming.
 
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