What physically push the cdl sensor closed? (1 Viewer)

[jb1dsl]

Trying to diagnose some 4wd issues and I am wondering what physically pushes the cdl sensor switch closed to light up the dash lights and allow the axle lockers to function? I pulled the sensor for the secong time and did the 9V battery clean but still no abs or cdl lights on the dash. Does the actuator on the transfer case physically engage the cdl or does the linkage connectd to the shifter? When I shift to low does it just drop into low range and the actuator is what physically locks the center differential? When I pull the sensor i can close it myself and the dash lights up and the axle lockers work and works when I do the paper clip trick. Can this connector that plugs into the sensor br physically wired to a switch in the cab to take the place of the cdl sensor??


Thanks

 

[jb1dsl]

Does anyone have the fsm on a computer that can send me the pages for troubleshooting the trouble i am having?

 

[lrowe_csp]

Search in the 80 forum for cdl. You will find at least two good threads that provide the complete fsm guidance for diagnosing this. I had the same problem, and wanted to let you know I have a known good working relay (transmission relay) that is in the driver side foot panel that I purchased from Cruiserparts while I was trying to figure out the problem with mine. I pulled and swapped my relays. wasn't the problem but helped narrow down issue and I put my original relay back in after I got the problem resolved. The relay is expensive, but I only paid cruiser parts $115 for the used one, if you need it, just pm.
Louis

 

[jb1dsl]

I have been searching and I guess Im overlooking what physically engages the cdl sensor. I will continue to research when I get time today. Will definitely keep you in mind about the relay. What was your final fix?

Thx

 

[96r50]

EDIT: I just read your question again and realized I didn't answer it! I'll try to answer it in another post. This post explains how the ECU knows the truck is in H/N/L range.


I borrowed these photos from beno's full-time to part-time transfer case thread. Note that in the second picture the case is upside down from how it mounts on the truck (Onur might
be practicing his inverted wrenching skills in case his truck ends up shiny side down ).

In this picture you can see the two switches (neutral and low range sensors) mounted in a V shape at the top of the backside of the transfer case. There is a round bump at the bottom of the V.

See the rod sticking out of the case at the 3 o'clock position? It is the "shift fork #1 shaft" and it moves fore and aft inside the case when you shift through H-N-L. There are divots on the end of the rod that trigger the 2 switches to tell the ECU what the transfer case is doing (the wiring diagram should explain how). Since it is directly connected to the shift forks in the case, if your truck shifts into low, this rod should be triggering the switches. You might have a faulty switch or a broken wire.

Hope that helps!

 

[96r50]

Alright, lets try this again!

In this photo (again from Onur's thread) you can see the front extension housing of the transfer case. At the top of it is the CDL indicator switch, just forward of the CDL actuator assembly. This switch is triggered by the "shift fork #2 shaft" which is connected to the CDL actuator motor. When the CDL actuator is triggered (either with the CDL switch or by shifting into low on a truck without to the Pin 7 mod), the actuator motor runs and tensions a spring inside the actuator. This spring remains under tension until the splines on the clutch sleeve line up, at which point the spring pulls the #2 shaft towards the centre differential, locking the diff. When the #2 shaft moves to the locked position it triggers the CDL indicator switch and tells it that the CDL is locked, and the CDL dash light should come on along with the ABS light.

Again, a faulty switch or a broken wire might be causing your troubles.

 

[jb1dsl]

So maybe it is the sensor that is bad in the v. From what i think Im reading the low range sensor sensor has to work to allow the cdl actuator to work, which then in turn presses the cdl sensor?? Or am I just crazy and dont no what Im talking about!?

 

[96r50]

That sounds right to me.

 

[jb1dsl]

which is neutral and which is low range??

 

[jb1dsl]

ok pulled both sensors at the rear of the transfer case and both showed quite a bit of resistance so i put them through the battery clean process. After that they read about 0.4 ohms so good contact. Put them back in and still no cdl or abs lights. what kind of voltage and resistance at the plugs and at the actuator? Can someone post the link to the exact process of troubleshooting the problem I am having, plz...

Thanks

 

[96r50]

I think the one furthest to the rear would be the low range switch

Now that I'm home, these might help.

 

[jb1dsl]

According to the drawing it looks to be the one on the right if looking from the rear. Like I said I pulled them and did a battery clean but no change. Not sure what to do next. At a loss right now....

 

[jb1dsl]

Where do i connect a 9v battery to see if the cdl runs? I had the LC with the key on but not running and put my ear to the drivers side kick panel and shifted into low range and i heard no clicking, arent I supposed to hear a click when i shidt to low from the transmission relay?

 

[ForealBoreal]

Its similar to the rear locker.

There is the locker mechanism and there is also a little switch in between the diff housing and the locker mechanism. If you were to take its two bolts out you would see the shaft that the locker motor pushes into the differential. There is a bolt attached to that shaft and when the locker is activated that bolt is moved (along with the shaft and it pushes a switch that lights up the light telling you that your locker is now locked.

If there needs to be some clarification I will take a picture of it to explain it to you.

 

[jb1dsl]

If there needs to be some clarification I will take a picture of it to explain it to you.

plz do

Here is one thing the owner of the LC took the console apart to fix the wont shift out of park problem. You could mash the brake and it stayed locked. He took the console apart and took a zip tie and used it to hold the locking mechanism from locking so now you can shift from park anytime (no brake). Is there something console that could have got unplugged that would send a signal to the ecu or trans relay?

 

[jb1dsl]

96r50,
In picture three, the white plug coming out of the actuator, is that the plug with pins 2&3 in it that you need to connect a battery too and see if the actuator motor works?

Found this too and it has the step by step troubleshooting:
Troubleshooting the Toyota FJ80 Land Cruiser Center Diff Lock (CDL) | Pacific Northwest Backroad Adventures

 

[OGBeno]

96r50,
In picture three, the white plug coming out of the actuator, is that the plug with pins 2&3 in it that you need to connect a battery too and see if the actuator motor works?

Found this too and it has the step by step troubleshooting:
Troubleshooting the Toyota FJ80 Land Cruiser Center Diff Lock (CDL) | Pacific Northwest Backroad Adventures

Nice find.

 

[bpassmore]

plug your hazzard switch into the cdl lock harness in the dash and see if you get the light to light up.

then do pin 7 mod to have some fun for the day.

sometimes my cdl lights wont come on until i move a little bit.

 

[jb1dsl]

Where is the cdl lock harness located behind the dash? My mind is going a hundred different ways, how will this prove what I need to fix?

 

[bpassmore]

Where is the cdl lock harness located behind the dash? My mind is going a hundred different ways, how will this prove what I need to fix?

it removes the plunger from the loop IIRC. on my 97 (95-97) it is in the center console above the radio and ac. harness is present, just has a dummy plug in it. i bought a hazzard switch from a 93 tacoma and plugged it in to mine. i got it for $.50 from a salvage yard.