P0705 code popped on yesterday

Apparently something is wrong my transmission. I have a CE light on and my scanner says is P0705 which is http://helpforcars.net/obd_codes/p0705_toyota.html

My truck is automatic and I noticed today that my 2nd gear isn't working properly. I can put the shifter into 2 but it acts as if its in D. If I put it into 3, it remains in 3rd gear like normal. Has anyone run across this?

 

Look into those TSB's it lists.

Sounds to me like for transmission range switch is acting up.

 

So I did some sleuthing around the bottom side of my truck around the transmission. I found what I believe is the Transmission Range Sensor on the transmission and I fiddled around with the plug going into it and BAM, no more check engine light.

I think I will get back under there, use contact cleaner and maybe some dielectric grease. It hasn't been on for two days now.

 

So the light has came back on after a couple months. I used contact cleaner but it isn't going away now. I'm pretty sure it is the same problem though because my issue with the 2nd gear is back. When I am in D, my 2 is lit up along with D.

I've tried unplugging the plug and plugging it back in. I have a feeling the entire part might be going bad or the contacts on the part have corrosion. I'll snap a pic and post it here

 

Here is the plug I am referring to. The assembly has a 7111 printed on it but I cannot find the part online yet to what it is. So far it is looking like the transfer case actuator. I found this thread http://www.pirate4x4.com/forum/toyota-tacoma/898689-2005-tacoma-get-fj-cruiser-t-case.html with the same part and saying how he is tired of cleaning it. It makes it so you cant manually shift into gears which is my issue. I cannot shift into 2nd. Looks like I need to take the part off and clean it

 

I beleive the part in the picture is the transfer case motor used to select between 2hi and 4x4 .
The code you have deals with the PRNDL switch as Spoon mentioned above .
Have a peek at page 16 on this pdf and it will show you the switch .
http://www.toyotatundraforum.com/pdf/A750E.pdf

You can use part of this illustration to diagnose your code but check the easy stuff first http://www.scribd.com/doc/18857706/TSB027709

Here is a fellow member who recently had issues with his switch
http://www.tacomaworld.com/forum/2nd-gen-tacomas/254595-sticky-tranny-shifter-2006-auto-6-cyl.html

 

Regarding page 16, what switch are you referring to? I read through that other TW post. I am not having symptoms hard shifting or not being able to shift into 4WD. My problem is I cannot shift into 2nd gear. It'll automatically shift into 2nd when I am driving in D, but if I manually shift into 2nd it wont work. The other post sounds closely related though.

It seems the same module I am talking about could be the culprit. I really want to take it off the transfer case and give it a good cleaning since I cannot get a clear view to see if corrosion is present since the prongs stick upward.

 

Too many sensors on page 16, i agree but page 15 shows a good view of the Park Neutral sensor and ..try page 36 also showing the sensor . Give both of the sensors a good cleaning . A dentist mirror is what I use to check the upward electrical prongs but there is nothing wrong with taking the sensors and motors off and cleaning them up .
Will the truck start in park and neutral ?

 

yeah the truck starts fine in P. Haven't tried starting it in N. I saw what sensor you're talking about on page 15. And good idea on the dentist mirror. I'm at work right now, but I should have one somewhere. I'll see if I can get a better angle that way

 

So I removed that part that I pictured above. I removed it and cleaned all the contacts. I also put some dielectric grease through it, but to no avail, check engine light remains. I will be cleaning that other sensor you mentioned from that document on page 15/16. I ran out of time yesterday. There is quite a bit of dirt and mud caked around it. Fingers crossed it fixes it.

 

My truck did the same thing when it was brand new. Check engine and Trac Off lights came on and when I would put it in D, 2L would light up as well.

Toyota replaced the ECM and everything has worked fine since (knock on wood).

 

Yea I think that sensor you pointed out is the tcase sensor that tells the truck if you're in 2 or 4 or hi or low or something so I'm not surprised that didn't help.

This also probably won't help but I had that code come on once. I had some reverse lights that could be turned on with a switch or when the truck was in reverse they came on automatically. I didn't use a diode, so if I had the lights on with the switch for more than a couple minutes it would back feed and make the truck think it was in reverse and what ever other gear I really was in.

Good luck, sounds like that transmission sensor might need to be replaced

 

I may take the truck into toyota so they can just diagnose the issue and not do any work if cleaning and greasing the park/neatural switch doesn't fix anything.

The reason I thought it was the the part I pointed out was when it first came on, I unplugged and plugged that back in and it went away for a couple months.

When it came on again, I did the same thing, went away and came back the next day (did this a couple times). I cannot get it to go off at all now.

 

I think you are going to get lucky when cleaning the Park Nuetral switch . The transfer case motor and the Park Nuetral switch share some of the same ground wires . Makes sense that after you cleaned up the transfer case motor the light went out because you restored a common ground .
Pop some pictures when you get the connections apart

 

So i got the park/neutral switch pulled out. Nothing was really corroded but I lightly sanded the contacts anyway. I then packed it with some dielectric grease and put her all back together. Still no luck

Still 2 is lit on my dash while in Drive and it is unusable. One thing I couldn't do that I found online was someone actually took their park/neutral switch apart and cleaned all the contacts and regreased the inside. This was done on a t100 and he was able to screw it apart. Ours, sadly, is riveted shut (although appears exactly the same).

Here is that thread:

 

Sorry dude . I was hoping a good cleaning would have done it . This is one of the problems when manufacturers place electronic components with printed circuit boards in the most extreme environment possible .
Do you take your truck swimming or a lot of rain/snow in your area ?
I agree that Park Nuetral switch probably has water impregnation and portions of the printed circuit board have failed . A common issue on Chev Ford and Dodge .

 

PRNDL errors have been pretty common on all vehicles for years. The trick is to learn HOW they work, then check to see why you have the problem you have. Looking at the wiring diagram for your truck it shows that voltage is supplied from the 10A IG1 fuse. This can be found at the transmission connector (NOT the transfer case connector) at terminal #2. It will be a yellow wire. (not to be confused with the yellow wire at terminal #3) Interestingly enough, the yellow wire at terminal #3 is the signal to the computer for 2L, which is where your problem appears to lay. The following is the wires, terminal location, and circuit:

1. R-W color, Reverse position
2. Yellow color, Power input
3. Yellow color, 2L gear position
4. not part of indicator circuit
5. not part of indicator circuit
6. G-B color, Park position
7. L-B color, Drive position
8. R-Y color, Low gear position
9. L-W color, Neutral position

According to this, if you were to CAREFULLY use a jumper wire between terminals 2 and 3 (the two yellow wires) your shift indicator should show 2nd gear. If it does, then you know the switch itself is bad. If not, then you have another issue. Looking through the full circuit you also have a part called a "Shift Lock Control ECU". If that part has failed, then you will also get an incorrect indicator when in 2L. This Shift Lock Control ECU is what controls power to the LED on the shift indicator in the cluster. This would explain why the transmission shifts fine, but when in 2L selected gear, you have a problem. I would most likely think your problem lies with this module, which is part of your transmission floor shifter.

 

^^^^^^ Thanks again Bama !!

I sure miss my susbsritption to All-data . Kinda lost without being able to look at schematics .

 

I couldn't run my shop without wiring diagrams. I'd be broke!

 

They were all good suggestions, I appreciate your input and advice. Fortunately, no. I've never gone in water with it I've never taken it in the snow.

Thanks for your reply. You seem quite knowledgeable in this stuff!

First, how to I distinguish between terminal 2 and 3? Do you have a reference somewhere? I have gone into the fuse panel and checked the 10A IG1 fuse and that appears to be working.

Second, is there a difference between 2 and 2L?