4WD light stays on?

skiezo · February 8, 2014

Hey guys,new to this forum and glad I found it. Lots of useful and great helpful information here.

Now on to my issue.

I have a 2001 Sierra SL 4WD ext. cab. It is a 5.3 with an automatic. It has a manual 4WD level,not the push button. This is a second vehicle, not my primary driver.

The other day I was taking the wife to work in some snow/ice and had to use 4WD at some points.

All was fine and when I shifted into 2HI the little 4WD light on the dash stayed on. The truck does disengage as well as engages into and out of 4WD manually by the floor mounted lever but the lite will not go out.

What would be the issue as I do not like the light staying on all the time.

Any help as to the cause as well as a fix?

Thanks Brian

kstruckcountry · February 8, 2014

If the light is still on, the front axle is still engaged. I'd assume the actuator is bad.

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skiezo · February 9, 2014

So even tho I can disengage the transfer case via the lever on the floor the front axles can still be engaged.

When it is in 2wd via the lever it is not in 4wd. That I know as I was driving in snow/ice and lost traction on some hills,but when I put it in 4wd it is in 4x4.

Is there any way to check to see if the front axles are engaged or disengaged?

kstruckcountry · February 9, 2014

Yeah that's right. If you can have someone watch the front driveshaft you'll know for sure. It shouldn't turn when it's in 2 wheel drive. It's the driveshaft from the transfer case to the front axle.

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Edited February 9, 2014 by kstruckcountry

CapitalTruck · February 9, 2014

The current flow to the dash light is controlled by the actuator in the front differential. Your transfer case might not be in 4wd, but my best guess would be that your front axle is still locked in, hence, your front driveshaft is still rotating. Like the other poster said, your front actuator is probably shot.

Edited February 9, 2014 by CapitalTruck

skiezo · February 11, 2014

OK thanks.

Will it be ok to run the truck like this for 50 miles or so? On my old F150 I would leave the hubs "locked in" in times of inclement weather. I do have another vehicle to drive but will need to take the wife to work if we get all this snow that they are calling for on Thursday.

CapitalTruck · February 12, 2014

I don't think it will kill it for a relatively short time period. At least the transfer case is disconnected so there is no power going to the front axle. I would try to get it fixed so excessive wear doesn't occur in the front diff.

tbeevrs · January 15, 2018

Did you ever figure out what was causing this? I've got the same exact problem on my 2007 Silverado. I disconnected the actuator and the light stayed on. Going to check and see if the front drive shaft is turning tomorrow.

carnau · January 15, 2018

4 minutes ago, tbeevrs said:

Did you ever figure out what was causing this? I've got the same exact problem on my 2007 Silverado. I disconnected the actuator and the light stayed on. Going to check and see if the front drive shaft is turning tomorrow.

Is your 2007 an classic body style truck?

tbeevrs · January 15, 2018

52 minutes ago, carnau said:

Is your 2007 an classic body style truck?

Yep, sure is

carnau · January 15, 2018

57 minutes ago, tbeevrs said:

Yep, sure is

Is it saying Service 4 wheel drive or anything on the dash?

tbeevrs · January 15, 2018

Just now, carnau said:

Is it saying Service 4 wheel drive or anything on the dash?

Just the light saying it's engaged is on. I can engage it into 4 Hi and into 4 Low and back to 2WD and the light stays on. Could it be the sensor?

carnau · January 15, 2018

47 minutes ago, tbeevrs said:

Just the light saying it's engaged is on. I can engage it into 4 Hi and into 4 Low and back to 2WD and the light stays on. Could it be the sensor?

In your glove box there are a list of RPO codes.

Should say NP#

Ramian17 · March 1, 2022

On 1/14/2018 at 8:22 PM, carnau said:

Anyone find the answer to this riddle. I have the same problem 2006 Sierra 3500 manual T case light won't go out. New front axle actuator, and a new t case selection switch. Light still on. Tried disconnecting both, separately and together. Light still one. Thanks for any help.

Sullya2016 · April 30, 2024

I have a 2006 Silverado with the same issue. Brand new front diff actuator. 4wd engages and disengages as it should but the light stays on. The indicator will only go off if I unplug the actuator but im no electrician by any means at all so

definitely in need of guidance of where to go from here