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Discussion Starter #1
Well I did the Atrac hack on my 07 with great performance and no issues. I am in Ouray for the summit now and actually am supposed to be a trip leader. I'm on Corkscrew yest, and when I shift into 4WD high, no 4wd lights come on the dash. I go to 4wd low and only get the "skidding car" light. No 4 wd light, no atrac light, nothing. I can lock the rear diff and go over in 2wd with rear locked. The cpu is killing my engine in steep turns since it is correcting wheel spin. 1/2 way over, I look down and my atrac light and 4wd light are on--alls good, but now no 4wd again. My connections look good, fuses good, etc.
I searched, but can not find info on this. I will recheck everything tonight, but if I cant figure it out, I'll undo my hack and take it to the dealer. Did I fry the computer? If it is replaced, can I put a post 07 on it so the atrac + locker together is not an issue?
Be patient, I am in our condo in Ouray, and have to walk a block to get wifi
Thanks, I've got to get this fixed, pronto!
Gary
 

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There is a possibility that one or more of the 3 sensor switches on the Tcase has failed. They can be bypassed with a jumper wire to test this. If they don't work the 4wd computer will not let the ADD motor engage the front axle. There could be a problem with the ADD unit itself. I have a manual trans which only has 2 Tcase switches and I've replaced 3.
 

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Welcome to the club. I've had ongoing problems with my 4 wheel drive system for at least the last 2 years. I've had the sensors replaced twice and the ADD Actuator replaced once, and guess what, I'm still having a problem. I had my tech install a bypass switch so that whenever one of the sensors fails I can hit the switch and have 4 wheel drive even with the sensor failure. The electronic 4 wheel drive system in the FJ is WAY too buggy for my taste.

Jim
 

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Discussion Starter #5
OK guys, good info. I did a batt disconnect to reset the ecu, checked fuses, and was bascially making myself crazy. I couldn't figure out why the front axle would kick in after an hour of off-roading. This makes sense now. I hope the local Toyota guys don't have a spasm due to my a-track hack. I can undo it, but had rather not.
I don't frequent the forum as much anymore, but have not heard of this as a problem. I don't mind running most things here in 2 WD with rear lockers, but think it is irresponsible to be trip leader with this. I can go to Grand Junction Mon. I will see if Montrose has a dealership, which would be best. If anyone has service suggestions, let me know. I'm out here a lot, but have not been to a Toyota dealership here.
I have a beast of a Jeep that I keep out here, but everytime I drive it, it makes me love my Toyota more (not so much today)
Thanks again guys
Gary
 

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Do you have a rear locker hack as well? Otherwise, how would you be able to actuate the rear locker if the computer doesn't know your in 4LO?
 

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Discussion Starter #8
layonnn, that is a good point and one I wondered about myself. The green 2 4WD indicator does not light, yet I can engage the rear locker. The light comes on and I hear/feel it engage. Based on this, I assume the front actuator is out and the 4WD indicator is tripped only when the front end engages, not just when the actuator recieves power. Is this correct? Otherwise, I can't explain. I DO NOT have the rear locker hack. I hope this is not some weird computer bug. Come to think of it, I believe I locked the rear diff with the atrac button off. That doesn't make sense to me either. I guess I will see what Toyota says Monday. It sounds like this has not been a problem with the atrac hack itself, but I am still wondering if I should undo it before I take it in (47K miles and extended warr)
 

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Discussion Starter #9
To bed. A cool star filled night in Ouray. Pretty darn nice even with a 2wd FJ when I paid for 4
 

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I've gone through two ADD actuators and have the 4WD sensor that was in in the transfer case replaced with a manual switch. In my experience, if the actuator is bad but the sensor is good, your red 4WD light in the dash will flash. If that light is not flashing, then I would suspect the 4WD sensor in the transfer case. Good luck with it in any event.

I agree with Jim, the system is way too complicated and doesn't need to be at all.
 

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Do you have a rear locker hack as well? Otherwise, how would you be able to actuate the rear locker if the computer doesn't know your in 4LO?
layonnn, that is a good point and one I wondered about myself. The green 2 4WD indicator does not light, yet I can engage the rear locker. The light comes on and I hear/feel it engage. Based on this, I assume the front actuator is out and the 4WD indicator is tripped only when the front end engages, not just when the actuator recieves power. Is this correct? Otherwise, I can't explain. I DO NOT have the rear locker hack. I hope this is not some weird computer bug. Come to think of it, I believe I locked the rear diff with the atrac button off. That doesn't make sense to me either. I guess I will see what Toyota says Monday. It sounds like this has not been a problem with the atrac hack itself, but I am still wondering if I should undo it before I take it in (47K miles and extended warr)

Off the top of my head I believe that the rear locker is only tied to the 4lo sensor. It sounds like the 4hi switch (transfer case sensor) is one of the ones that went out or is not working. Therefore your locker will still work in 4Lo - but the ADD will never actuate since the transfer case sensor or ADD itself is not working.

With the Lefty Transfercase I can leave the 4wd lights off (tied to a seperate switch) and shift into 4Lo and the "skidding car light"comes up on the dash. I then have ability to use the rear locker. Based on this I'd say that that switch on 4LO/locker is working fine and either the 4hi or ADD is borken.


Basically the same thing that Lee said.
 

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Discussion Starter #12
Well guys, that is making some sense--here is something weird, though. I can lock the rear axle with the lever in 4H or 4L, but the 4WD icon never comes on. I have never been able to rear lock in 4H-again, I don't have the locker hack. So the 4L switch has 2 parts? One switch that operates the actuator (not working/open) and one that entergizes the rear locker switch (burned out in closed position?)
I can not lock the rear in 2H.
It makes sense that it is a switch and not actuator problem, but still confusing to me.
I agree that this does seem like an overly complicated set up with too many moving parts for what needs to be accomplished.
I hope the dealership can fix this rather quickly, I'm going to be needing my FJ!
Gary
 

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I had both the 2h-4h and 4l sensor go out and just hacked in and added switches in the cab no more problems!!
 
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