Pesky Center Diff Indicator (1 Viewer)

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Brentbba

Former Golfer
Joined
Mar 27, 2003
Threads
429
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10,846
Location
OC, CA
Ok, center diff indicator and ABS (yes, I have ABS) indicators have not been coming on when shifted into 4L. The truck is shifting to 4L. Very definite change in handling and feel of her, so I know she is in 4L.

Did all the reading thru search on similar issues. As opposed to trying the cleaning approach others have been successful with, I replaced the Center Diff Lock Inticator Switch supplied by our local parts/must feed dogs wizard. Out with the old, in with the new fairly easily, despite the location of the SOB.

Still nothing. I can hear the Center Diff Lock Control Relay clicking under the DS quarter panel, so I assume the relays are working ok. Pull it anyway and test per Parts Inspection section of FSM page TR-55. Perfect continuity between terminals in (a) and had bro-in-law test to ensure the diode between terminals 6-7 is ok. He's got better test equipment than my little multimeter (yes - I have one Dan, and learning how handy it is to have around :D ). Follow section (b) and everything there checks out ok as well. Doesn't appear that the relay is a problem.

No blown fuses on either panel. Center Diff light does not come on when I turn the key to see all the idiot lights on the dash. Is that normal. The F and R dif lock lights do come on for a second.

Is there another relay, wiring harness, etc. I should check. Seems the signal is getting to and from the relay OK, just not any further to let the truck know it's ok to engage the front and rear lockers. Everything was ok in Jan/Feb when I excercised them last.

There are two actuator switches on the transfer case that I saw. Pulled the one sticking straight up first and quickly found out that one wasn't the Center Diff Lock Indicator Switch (the harder of the two to get to pointing to the PS) as the electrical connectors didn't match. Could there be a problem with that one. Switch was exactly the same as the Center Diff Lock Indicator Switch on it's body. Only the connector was different.

Comments, suggestions, other items to test? Tried to be as detailed as possible as to what I did to rule out things.

ps - front brake pads went on in a snap. Damn glad I did them this weekend. Down to 2mm! :whoops: Trip to Kernville rafting with the scouts next weekend and didn't want to travel the grapevine with pads I knew were close to toast. Water flow for rafting should be great with all the rain/snow we've had this year. Can't wait! Thus the need for the brake pad change now! hehehe
 
After a quick skim of your post, my bet is a faulty low range sensor on the t-case.

I would temp rig your hazard switch as a CDL switch and see if that will produce desired and expected effect.

If it does you have nailed the problem, which, if you have a CDL, is not all that necessary to fix.

A way to determine if the CDL light is at fault would be to engage the CDL by low range or otherwise and then checking to see if the FR/RR difflocks will engage. If they will engage you know the CDL is locking.
 
I got stuck once because of this problem but it corrected itself before I got around to trouble shooting it. My guess is you can't engage the diff locks because the computer doesn't recognize that you are in low. Sounds like the transfer sensor to me as well, but that is based purely on deduction rather than experience.
Good luck and keep us posted.
Dan
 
Don't have a CDL Switch and the FF/RR will not lock up. Thought it was the sensor you are talking about that I replaced?

Dan, IdahoDoug, any ideas?
 
Goldfinger recently had a similar problem IIRC and went through hell trying to figure it out, you might PM him and see how he resolved it. To tell the truth I couldn't tell you which sensor was which but I think there are two that can affect the computer and the center diff. Somebody please correct me if I am wrong on that
Good luck
Dan
 
I had this problem except the sensor from the tcase didn't work right and my dad drove the truck witht he CDL on for two weeks :eek:, guy pushed it when he took it to a car wash. Low and behold I ended up replacing the front driveshaft because of it :crybaby:. Mine CDL was engaging just the light on the dash wasn't showing up. Try checking the transmission control relay again?
 
High Brenttba,

I had a similar problem with my CDL which has now been resolved, care of a small country garage I could not deal with it my self because of lack of cover and it was very muddy here. I downloaded as much information as I could find to guide them as they had not talked this problem before. On activating the CDL switch or going into Low I too could here the relay clicking away to its self from memory I could not here the motor but my threads may reveal this. To cut a long story short they told me that the CDL Actuator was broken and not operating it turned out to be very expensive here and DAN offered and supplied me with a new one, thank you again Dan. After fitting the actuator I was told that it was all working now but I tested it by getting it Cross Axled at home as I have the land and discovered that it was not working but I could here the motor twirling when I asked my wife to dive over me, well I mean repeat what I had done with me risking life and limb underneath. They looked at it again and said that a switch was not working I could not remember which one they indicated too so I bought the Low indicator switch at the back of the transfer box as I had taken this off my self to test it and found that it was not working, but this did not fix the problem but the low indicator light on the panel now lit up when I put it into low which it hadn’t before. So I removed the other switch at the front right hand side of the transfer box which proved also not to be working when I tested it with a metre. I installed this my self and was very pissed off to find that I still had no CDL locked. I was very frustrated as I desperately needed all my locks working because of were I live and the weather threatening. The garage sorted the problem very quickly they told me that the switch did not work with its supplied washer and so they put a thinner one on and hay presto I have all three diff locks working :D :D :D . This all took quite a while to fix because of lack of experience on my part and the garage going backwards and forwards to the little garage then into the nearest town with a Toyota Dealer to enquire about parts, the fastest part of the whole operation was ordering the parts from CDAN and having them delivered to my home. In fact I rang him when they came into the UK and he told me that he had only sent them the day before that was incredible because the local Toyota dealer could not do it that fast :beer: .

Pointer, check the switch at the front RHS of the transfer box near the output shaft.
http://www.sleeoffroad.com/technical/tz_centerdiff.htm

Good luck and let us now how you get on. :)
 
Goldfinger - first, agree 100% about Dan. There is no finer!

Reread Kumar's writeup on Slee's site. Old switch was definetely bad. Simple omh test on the old switch showed about 185 omh's when 'on'. May have to pull new switch and test it and perhaps reinstall w/o the washer and see what happens. Now that I know what I'm doing, it's a 5 min job to remove and reinstall.

What's the similar indicator switch on the top of the transfer case? Anyone know?
 
Ok a good laugh at my expense. Being a 1/2 and maybe now demoted to 1/3 :banana: mechanic.......I'd put the new switch from Dan in the L4 position indicator and NOT the Center Diff Indicator. I'd changed the wrong indicator! :whoops: As our most helpful Dan patiently explained in a phone call, the Center Diff indicator was at the FRONT of the transfer case (what the hell is that anyway - just looks big to me) not in the rear with the neutral indicator right next to it. He gave me the FSM page to look at showing all three switches. Got home, took a quick look and figured out what 'should' have been done in the first place.

Did the paper clip jumper on the CORRECT connection and lo and behold, the Center Diff light went on. Swapped out the bad switch for the one I'd removed from the L4 and I had working indicators. Front diffs locked up right away. Rears didn't want to this evening. May try again at the camp site this weekend on dirt roads. They don't get much 'exercise' with me.

:cheers: to Dan for calling me on an extremely busy day for him after being on vacation enjoying Moab. Truely top notch customer service.

My thanks Dan!!! :bounce: :bounce: :bounce:
 
Brent,

I am delighted to hear that you have that all sorted out. I am sorry that I was not able to assist sooner than I did, My wife gets a bit sideways if I do not take a break once in a while, so in order to maintain the peace I must....:rolleyes:
 
cruiserdan said:
Brent,

I am delighted to hear that you have that all sorted out. I am sorry that I was not able to assist sooner than I did, My wife gets a bit sideways if I do not take a break once in a while, so in order to maintain the peace I must....:rolleyes:

What kinda excuse is that??? :)
 
Eduardo96FZJ80 said:
What kinda excuse is that??? :)

Sounds like a damn good one to me! :D

Jeez Dan - give yourself a break. I wasn't even expecting a return call, etc. until at least today. I think we all know how buried we are returning from a week of vacation. Ok...comment for working folks only, not the youngsters still studying.
 
Thanks To Everyone For Contributing to This Thread. I just did this and fixed mine as well. Here are some pics of what was discussed! My switch is on the way from dan!

tcaseindicator.jpg


and

tcaseindicator2.jpg
 
Yahoo! :bounce: :bounce2:
 
Yeah, pretty stoked, something odd though, my lights come on in both Hi and Low. I think it might be because of the 7 pin mod i just did. We shall see, switches should all be here today!

I think this should be a sticky in the FAQ
 
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