01 4Runner Won't Disengage 4WD

[theonlycola]

Big Update! I tried to jump the actuator and it sounded like it wanted to go but couldn’t. So I pulled off the actuator cover which also houses the motor and low and behold some of the connection channels are broken. At this point there are 2 options, try to solder in the connections which I’ve seen people do with the front actuator, or go tear a cover off of a scrap car. Neither of these would require me to split the T-case

 

[theonlycola]

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[VGKBlackhawks]

Engaging 4wd and engaging the center diff lock are TWO different things (4wd round button and dash button), why would you turn them both on at the same time on solid pavement? yeah realize you were 'fiddling' but the center diff isn't something to fiddle with on solid roads.

Now you can try following the instructions under the driver visor adding the "make a slight right/left turn" to 'help' the system with gentle throttle pressure. Next change fluids, several times. If that doesn't work then start testing via the FSM procedures. Luck and enjoy that runner. :cowboy:

[MENTION=75316]jgue467[/MENTION] I have an 01 SR5 that does not respond when the CDL button is pressed... no light, no click. 4hi/lo work just fine. I've searched a good amount and read the new user stickies, but can't seem to find information on troubleshooting just the CDL. Have you seen any posts about CDL only issues? I don't have the FSM yet either. Is it in there?
I apologize if there is an obvious thread on this. I've followed many of the standard 4WD engagement threads with no luck.
Thank you!

 

[Bad Luck]

[MENTION=75316]jgue467[/MENTION] I have an 01 SR5 that does not respond when the CDL button is pressed... no light, no click. 4hi/lo work just fine. I've searched a good amount and read the new user stickies, but can't seem to find information on troubleshooting just the CDL. Have you seen any posts about CDL only issues? I don't have the FSM yet either. Is it in there?
I apologize if there is an obvious thread on this. I've followed many of the standard 4WD engagement threads with no luck.
Thank you!

Does it go into 4hi unlocked?
Have you checked the switch for continuity when you push it in?

 

[VGKBlackhawks]

Does it go into 4hi unlocked?
Have you checked the switch for continuity when you push it in?

Hello! Thanks for the reply. I managed to track down a wiring diagram for the 2002 that was advertised as usable on the 2001. It doesn't match the pin numbering or the wire colors on the connector to the switch.
There are 4 contacts wired in the 10 pin connector. 1 at the top of the connector is a ground, the one diagonal from that has 12VDC when lights are on. These aren't on the 4WD schematic (briefly looked at interior lighting. Not there either). The other 2, also diagonal from each other at the bottom of the connector, one shoots to about 40 ohms to ground, but it moves around at first, then settles in as if I'm shooting through a component. I assume this goes to the 4WD ECU as the diagram states (just not the correct pin number or color). The other shoots open to ground and never has voltage in any 2 or 4WD position (2WD, 4WD H, 4WD L). I shot the contacts on the back of the CDL switch depressed and released. I never got continuity. I was apprehensive about jumpering the contacts on the connector as I couldn't really trust the diagram I had, but I did it anyway. It had no effect in any 2 or 4WD configuration.

Things I found odd:
The switch never makes continuity. Is it a relay type switch? It doesn't read as such in the diagram.
One of the contacts that go to the CDL switch should be a spliced ground according to the diagram. I'm not sure if it is always a ground, but it appears to be if I am reading the diagram correctly.

The CDL switch was very easy to get out. It appears that someone was already troubleshooting this before I bought it. I didn't test it before I bought it. I was on pavement and 4WD worked fine. Dude said it worked.

The diagram doesn't list what type of signal is on the wires to and from the 4WD ECU. That would be helpful.

Thanks again for the reply. Any help is appreciated.

 

[Bad Luck]

[MENTION=414251]VGKBlackhawks[/MENTION]

Does it go into 4HI unlocked?
Have you tried applying power and ground to the transfer case shift motor on the transfer case? That's what controls your 2wd/4hi/4hi locked operation in the transfer case.
Are you performing all the circuit testing on the switch with it disconnected from the harness?
You need to find an electrical wiring diagram manual for a 2001-2002 4Runner. They share the same 4WD system and should be majority the same for both years.

 

[VGKBlackhawks]

[MENTION=414251]VGKBlackhawks[/MENTION]

Does it go into 4HI unlocked?
Have you tried applying power and ground to the transfer case shift motor on the transfer case? That's what controls your 2wd/4hi/4hi locked operation in the transfer case.
Are you performing all the circuit testing on the switch with it disconnected from the harness?
You need to find an electrical wiring diagram manual for a 2001-2002 4Runner. They share the same 4WD system and should be majority the same for both years.

[MENTION=319302]Bad Luck[/MENTION]
2WD/4HI/4LO all work fine unlocked using the 4WD switch for 4HI and lever for 4LO in the cabin. It transitions to and from each mode pretty quickly. The CDL switch is unresponsive in all modes. I can hear the actuation and see the indicators in the dash flash (4 green and center yellow) until engaged. Thee CDL yellow light doesn't flash any other time.

I have a schematic diagram for a 2002, but it doesn't match the pin numbers or wire colors at the switch. I assume it will be different at the ECU as well. I was going to check continuity from the CDL switch connector to the 4WD ECU connector, but I don't know what pin it will be on at the ECU connector. The diagram shows a straight run, so I could assume it was correct as soon as I found 1 and only 1 wire with continuity.

All testing was done at the switch connector and the pins on the back of the switch with it removed. I could shoot at the back of the connector with the switch connected. I didn't think to do that. I'll try that after work and post results.

Thanks again!

 

[Bad Luck]

[MENTION=414251]VGKBlackhawks[/MENTION] Where did you source the wiring diagram from? If you're going to back probe while diagnosing the switch I suggest using the min/max function if your multimeter supports it.

[MENTION=10169]TheDurk[/MENTION] Do you have an EWD that might help diagnose this? I have a 2000 EWD, but I feel like it would be different from the 2001-2002 4wd system.

 

[shadow247]

Bumping this to the top!

I'm stuck in 4wd, but the Front diff is not engaging. I can hear the ADD relay clicking when I short the 4wd Indicator Switch on the Tcase actuator. I'm leaning towards that 4wd Indicator being the culprit. I pulled, cleaned, and tested good, so i'm a bit stumped.

I am able to jump the actuator like OP and get the tcase to unlock the front driveshaft, and it engages instantly when I push the 4wd Button. My next test is to check the ADD actuator harness and see if I'm getting the 12 signal from the ECM. I have a feeling the 4wd Switch is testing good but just not actually sending the signal.

Will report back daily until this problem is solved.

 

[3bears]

Bumping this to the top!

I'm stuck in 4wd, but the Front diff is not engaging. I can hear the ADD relay clicking when I short the 4wd Indicator Switch on the Tcase actuator. I'm leaning towards that 4wd Indicator being the culprit. I pulled, cleaned, and tested good, so i'm a bit stumped.

I am able to jump the actuator like OP and get the tcase to unlock the front driveshaft, and it engages instantly when I push the 4wd Button. My next test is to check the ADD actuator harness and see if I'm getting the 12 signal from the ECM. I have a feeling the 4wd Switch is testing good but just not actually sending the signal.

Will report back daily until this problem is solved.

good luck and keep us posted

 

[shadow247]

good luck and keep us posted

Well I have good and bad news to report.

The 4wd is now working, but I can not pinpoint what was going on.

I believe the ADD actuator may have been stuck. I tried to jumper it to "engage" and it just groaned a bit. Jumper it to disengage and got a good sound out of the motor. Then I jumped it to engaged and it worked smoothly. I confirmed the front diff was engaged by spinning the front tires by hand and watching both front tires spin.

Jumped it open and closed a few more times, plugged it back in, and boom. 4wd instantly engages. I usually am rolling at 1-5mph when I engage the 4wd, but this weekend I was sitting in a line waiting to take off when I realized I had not engaged my 4wd...

I'm going to post up later once I study the pinouts on the 4wd ECU Harness. I believe you can jump the ADD actuator from there, as the power comes from the 4wd Harness. Can anyone confirm this before I go on a wild goose chase. Is there an ADD relay or separate computer somewhere under the dash?

 

[spartacus]

Well I have good and bad news to report.

The 4wd is now working, but I can not pinpoint what was going on.

I believe the ADD actuator may have been stuck. I tried to jumper it to "engage" and it just groaned a bit. Jumper it to disengage and got a good sound out of the motor. Then I jumped it to engaged and it worked smoothly. I confirmed the front diff was engaged by spinning the front tires by hand and watching both front tires spin.

Jumped it open and closed a few more times, plugged it back in, and boom. 4wd instantly engages. I usually am rolling at 1-5mph when I engage the 4wd, but this weekend I was sitting in a line waiting to take off when I realized I had not engaged my 4wd...

I'm going to post up later once I study the pinouts on the 4wd ECU Harness. I believe you can jump the ADD actuator from there, as the power comes from the 4wd Harness. Can anyone confirm this before I go on a wild goose chase. Is there an ADD relay or separate computer somewhere under the dash?

I've read on a thread here in the past that the ADD relay is behind the glove box on the fire wall for a 99. Since you have 2001 it could be different.

 

[Adamcam70]

2001 Toyota 4Runner stuck in 4wd last time it was stuck for 1 week it turned off then it snowed again so I turned it on again now it has been a week and it has not gone off and all the YouTube videos of the switch they replace in front of the transmission I can’t find that switch on my 2001 I’ll I can find is two switches on the t case but I’m not sure if that the right one too mess with. Please help. Thank you

 

[Auce]

I have an 01 and the 4WD is intermittent, but I'll always manage to get it out of 4WD. Putting it in reverse works sometimes. I haven't found why this happens though.

 

[vladen32]

Hey there,

I've been going over numerous posts trying to troubleshoot my problem, but I'm hitting a wall. Just to clarify, my vehicle is a 2000 4Runner equipped with the "I" transfer case, which means the manual 4L but High 4 and the center locker are electronic.

I've meticulously tested the actuator—it's in good shape. I've also checked all the buttons inside for continuity, and they're functioning fine. The Transfer Case Switch seems to be working as well. Despite all this, I'm still stumped. The one component I haven't been able to inspect thoroughly is the front differential actuator, mainly because of its tricky accessibility.

When I removed the actuator cover on the transfer case, I could disengage it from 4x4, and the indicator lights turn off upon reassembly. However, the issue arises when I attempt to engage all-wheel drive using the 4x4 knob—it engages and locks my center differential, but the blinking light persists. I have to manually disengage it by taking off the actuator cover and rotating the wheel to pull out the shaft from the transfer case.

I've even tested the motor with a 12v power source, and it seems to be functioning properly, with no signs of mud or debris.

I'm at a loss here. Could it possibly be the 4x4 module that the 2000 4Runners have? Any suggestions on what steps I should take next?