Center Diff Question

[GBinAZ]

When I tried to lock my center diff for the first time, the switch doesn't light up, no diff light on the dash, and I am not hearing a relay click in side the truck. It doesn't feel like the diff is locked when I drive in a circle, but my testing was very limited.

I am a newbie to the GX, have had an 80 for 10 years now, is there a method to locking the diff in the GX?

I tried it in 4 Lo and 4 Hi, with trans in N. No luck.

FYI, the rear air suspension was removed by the previous owner and the fuses pulled to kill the lights on the dash.

Any help would appreciated.

 

[Jstawgn]

There is a separate diff lock fuse. Make sure it's not removed. It's next to TEMS so it's possible they remove wrong fuse.

 

[JLee]

+1 to check fuse. You should be able to lock the diff without doing anything special - just push the button and the light should flash until it's engaged.

You can also check to see if the 4wd control ECU is firmly plugged in, though its absence would likely give you a christmas tree dash. It's screwed into the top of the plastic trim panel that's sitting underneath the glove box.

 

[GBinAZ]

Fuse is in place and intact... unfortunately. Will get out my multimeter to check for power and look at the ECU in the morning

Thank you both.

 

[JLee]

You can also test the switch - it's pretty easy, just a momentary switch that should have continuity across two of the connectors when the button is pushed. I forget which ones offhand - if you can't figure it out lmk and I'll see if I can dig up the relevant page in the manual.

If you have access to techstream, check for any codes too.

 

[GBinAZ]

Fuse in the cab is good, power going in and out. Plugs are firmly seated in the 4wd ECU.

Any tips on getting the switch out without damaging the center console ?

 

[JLee]

If I recall correctly, I ended up popping the whole trim panel and then pushing the switch out from underneath.

 

[GBinAZ]

so just the panel the switch is in can be popped out by itself? that would make things easier.

Thx.

 

[DSRTRDR]

just for clarification: you put the transmission shifter in neutral, and the transfer case shifter in low ? - did you the put the transmission shifter back into some gear ? - what lights when on in the dash then ?

 

[GBinAZ]

I tried it in 4 Lo and 4 Hi, with trans in N, No luck.
I tried it in 4 Lo and 4 Hi, with trans in D, No luck.
I tried it in 4 Lo and 4 Hi, with trans in L. No luck.

I did each of the above, with each of the below:

push the CDL switch and release, no lights on the dash
push the CDL switch, hold for 1 second and release, no center diff lock light on the dash
push the CDL switch, hold for 2 seconds and release, no center diff lock light on the dash
push the CDL switch, hold for 3 seconds and release, no center diff lock light on the dash

Etc...

When I put it in 4Lo, there is no indication on the dash, but I am not sure if there should be. And by this I mean no other indicators of any kind come on.

I got my DVM out of storage so I can now test the switch and then start my diagnosis if the switch is good.

 

[DSRTRDR]

if you want, we can meet up around Christmas and compare trucks . . . send a PM