Center Differential Lock Not Working in Low (1 Viewer)

[dpeshkin]

I’m gonna hijack this thread with an issue I’m having with my CDL. I have a 97, center diff lock button added by PO. And I can not get the cdl to do anything. The dash button used to work in either high or low so I know it used to work. Here’s what I’ve done to test it, used this thread for help and did all the tests.

Troubleshooting the Toyota FJ80 Land Cruiser Center Diff Lock (CDL) - Pacific Northwest Adventures

A step-by-step tutorial on troubleshooting the Center Diff Lock on a Toyota FJ80 Land Cruiser.

www.pnwadventures.com

- pulled cdl dash button from dash and tested continuity, it checked out.
- pulled relay from kick panel, tested continuity with and without 9-volt power. It checked out.
- tested all 3 switches on the tcase, they all checked out.
- tested ohms on the actuator and it checked out.
- hooked the actuator motor up to 9-volt power and it DID engage AND turned the lights on the dash, confirmed it locked by driving around, unlocked the cdl by reversing 9-volt power to the actuator motor.
- don’t know what else to test.

Pressing the cdl dash switch triggers the relay in the kick panel, I can hear it every time. But it does not engage the actuator. I also checked the 10amp gauge fuse and 30amp diff fuse. So I’m stumped. Any ideas out there? Everything seems to be working but there’s a lose somewhere from the relay to actuator motor.

Did you read CruiserDans response to the earlier post?
“when in low range the the shift points move up to a higher RPM. Very much like when you switch to the power mode. If the transmission shifts rapidly through the gears in low range the low 4 position circuit is not working.”

That means the low 4 position switch is sending a signal to the transmission ECU. This means the system is behaving as though pin 7 has been disconnected.

 

[Ecliff5]

Yes, when shifting into 4low the transmission shift points change and it is indeed in low range.
When trans is in park and tcase in neutral the a/tp light comes on the dash. When the center diff switch in tcase is pressed in it triggers the cdl and abs lights on dash. When actuator motor was locked and unlocked with 9volt power the lights on dash came on and off as they should also.

 

[L450X]

Yes, when shifting into 4low the transmission shift points change and it is indeed in low range.
When trans is in park and tcase in neutral the a/tp light comes on the dash. When the center diff switch in tcase is pressed in it triggers the cdl and abs lights on dash. When actuator motor was locked and unlocked with 9volt power the lights on dash came on and off as they should also.

Did you ever get this figured out, if so what was culprit?

 

[Ecliff5]

Did you ever get this figured out, if so what was culprit?

I did not, last time I went wheeling I locked it with a 9-volt battery, it unlocked itself on the trail and when I pressed the CDL button it locked itself back up. Kinda fixed itself at that moment, then it unlocked itself using the CDL button after doing some circles in reverse. Now the truck is in pieces lol.

 

[L450X]

I did not, last time I went wheeling I locked it with a 9-volt battery, it unlocked itself on the trail and when I pressed the CDL button it locked itself back up. Kinda fixed itself at that moment, then it unlocked itself using the CDL button after doing some circles in reverse. Now the truck is in pieces lol.

Lol ah the old trucks in pieces bit. Just got out of that stage. Good luck with it and thank you for the response, I’ll give that a go and see if I get similar results.

 

[HuyFZJ80]

Starting up an old thread.
Center diff won’t engage in 4L. Replaced the center diff lock switch and the low range position switch on the transfer case. Installed the center diff dash switch but it also didn’t work. Jumped one of the plugs off the transfer case and it lights up both ABS/CDL. I just tried to use the 9v battery direct to the actuator motor itself, but still nothing. Does that mean my actuator motor is shot, and needs to be replaced? Or should I be checking something else? Thanks

 

[L450X]

Starting up an old thread.
Center diff won’t engage in 4L. Replaced the center diff lock switch and the low range position switch on the transfer case. Installed the center diff dash switch but it also didn’t work. Jumped one of the plugs off the transfer case and it lights up both ABS/CDL. I just tried to use the 9v battery direct to the actuator motor itself, but still nothing. Does that mean my actuator motor is shot, and needs to be replaced? Or should I be checking something else? Thanks

From someone who removed the center actuator 2 times, while the TC was still installed… first test I’d do is temp pull your ABS fuse and then test the system/operation of the CDL.

Safety disclaimer: install ABS fuse when test is complete.

This test showed me that the problem was not the CDL itself, as it operates without the ABS fuse in.

 

[HuyFZJ80]

From someone who removed the center actuator 2 times, while the TC was still installed… first test I’d do is temp pull your ABS fuse and then test the system/operation of the CDL.

Safety disclaimer: install ABS fuse when test is complete.

This test showed me that the problem was not the CDL itself, as it operates without the ABS fuse in.

Thanks. I’ll give that a try later on today.

Question. How hard was it to remove your actuator? Did you drop the TC using longer bolts or can I just drop it using a jack to support it?

 

[L450X]

Thanks. I’ll give that a try later on today.

Question. How hard was it to remove your actuator? Did you drop the TC using longer bolts or can I just drop it using a jack to support it?

First I doubt it’s the actuator itself unless you know something likely influenced its demise (aka submerged the rig or heavy salt area) so would suggest exhausting all other options before removing.

It sucked getting it out of there, both times, but it’s “doable” while everything is in place. It’s just a lot of really short ratcheting wrench turns and a whole lot of well where the heck does my hand go. The. The even more fun part is the re install with some silicone gasket. Again avoid at as much as possible removing it. Because the disappointment of removing it only to find that it works is next level. Then to be so dumb (like this guy) that you do that a second time.. feeew that sucks.

If it worked before and doesn’t work now, but nothing known to influence its demise has happened, I’d bet it’s more on the simple solution side.

 

[HuyFZJ80]

First I doubt it’s the actuator itself unless you know something likely influenced its demise (aka submerged the rig or heavy salt area) so would suggest exhausting all other options before removing.

It sucked getting it out of there, both times, but it’s “doable” while everything is in place. It’s just a lot of really short ratcheting wrench turns and a whole lot of well where the heck does my hand go. The. The even more fun part is the re install with some silicone gasket. Again avoid at as much as possible removing it. Because the disappointment of removing it only to find that it works is next level. Then to be so dumb (like this guy) that you do that a second time.. feeew that sucks.

If it worked before and doesn’t work now, but nothing known to influence its demise has happened, I’d bet it’s more on the simple solution side.

Unfortunately I just purchased it last month, so I’m not entirely sure of its history. PO said he would occasionally go off pavement to get to secluded fishing spots (mild water crossings, etc) but cannot recall the center diff lock light illuminating on the dash. For reference, PO did not know how to wrench on anything, and relied on a local shop to do all maintenance (questionable work at that). I’ve verified that all the lights work on the dash as I’ve replaced them all with new OEM. Any yes, I want to try everything before I commit to yanking off the actuator as it sounds like a PITA.

 

[L450X]

Unfortunately I just purchased it last month, so I’m not entirely sure of its history. PO said he would occasionally go off pavement to get to secluded fishing spots (mild water crossings, etc) but cannot recall the center diff lock light illuminating on the dash. For reference, PO did not know how to wrench on anything, and relied on a local shop to do all maintenance (questionable work at that). I’ve verified that all the lights work on the dash as I’ve replaced them all with new OEM. Any yes, I want to try everything before I commit to yanking off the actuator as it sounds like a PITA.

Also not the most advised but there are 2 pins on the connector to the motor that a +\- 12v one could in theory power those with it in the rig to test the motor. Much possibility for oopsies in this but there’s that. YouTube shows some of those pins with a quick search

 

[HuyFZJ80]

Also not the most advised but there are 2 pins on the connector to the motor that a +\- 12v one could in theory power those with it in the rig to test the motor. Much possibility for oopsies in this but there’s that. YouTube shows some of those pins with a quick search

Yeah, I tried that route already using a 9v battery. I tried it again after pulling out the ABS fuse. No dice. I reviewed the FSM and tested the actuator using my multimeter. No resistance noted between pins 2 and 3. Sounds like it might be toast. Anyone have any suggestions before I look to outsource an actuator motor?

 

[WCBlueSky]

Yeah, I tried that route already using a 9v battery. I tried it again after pulling out the ABS fuse. No dice. I reviewed the FSM and tested the actuator using my multimeter. No resistance noted between pins 2 and 3. Sounds like it might be toast. Anyone have any suggestions before I look to outsource an actuator motor?

If you have time, I would try taking it out and rebuilding it. Inside mine, some sticky plug sealant dripped onto the contact plate which made it not work. I cleaned that up, added new grease, and it is as good as new.

 

[HuyFZJ80]

If you have time, I would try taking it out and rebuilding it. Inside mine, some sticky plug sealant dripped onto the contact plate which made it not work. I cleaned that up, added new grease, and it is as good as new.

After taking it apart, was it difficult to put back together? Also, what kind of grease did you use? I might have to take it apart when I muster the courage to do so. Haha

 

[Malleus]

There is a 100 series grease kit for the steering column that is ideal for the CDL motor in the 80 series and the 200 series, too. It also works well for the power window motors.

 

[jonheld]

Yeah, I tried that route already using a 9v battery. I tried it again after pulling out the ABS fuse. No dice. I reviewed the FSM and tested the actuator using my multimeter. No resistance noted between pins 2 and 3. Sounds like it might be toast. Anyone have any suggestions before I look to outsource an actuator motor?

Not understanding why folks are pulling the ABS fuse to test a motor. Makes zero sense as the ABS circuit is simply disabled once the CDL lock switch on the transfer case is closed. That's what illuminates the ABS dash lamp.
All schematics for all systems are available to download from the resources section in the Toyota EWD, and there is a diagnostic procedure for all systems in the Toyota FSM, again, available for you to download in the resources section.

 

[Malleus]

I'm starting a campaign to rename the Resources section "Don't Look Here".