P0705 Park Neutral Switch

Update:
I did the exact same "fix" Bobo describes above and the MIL or check engine light has gone off. I too did not see any visible signs of water or corrosion, but I used contact cleaner on the connector block and all 4 plugs that connect to it. I used some zip ties on the rubber boot in the engine compartment and then wrapped with electrical tape to help seal that entrance. This seems to have done the trick. Thanks a bunch tacomaworld and especially Bobo, Maxa and Joes06tacoma for their posts.

Helpful links with pictures:

This link shows pics of junction block and engine compartment entrance:
http://www.scribd.com/doc/18857706/TSB027709

This link has picks/instructions on how to remove the kick panel:
http://www.tacomaworld.com/forum/technical-chat/1475-05-drl-daytime-running-lights-install-oem.html

PS. I didn't go to the dealer, but you would think Toyota would offer a similar fix as opposed to charging several grand to replace a wiring harness.

 

Glad you got it taken care of. The TSB gives 4.5 hours to perform that job. Even if the dealer charges double that, at 100 bucks an hour that's 900 bucks. Charging over 1000 for a wiring harness is robbery.

 

had same prob on my 2005. park and rev light on and po705. dealer charging me $880 to repair coroded wiring and prndl switch.harness and block dry as a bone. getting it back hopefully today.

 

Bummer to hear that you are having to pay for that fix. I hope other members see this thread before they shell out big bucks. One other thing that I noticed when I fixed mine. There was a small hole (Factory type) in the left wheel well that probably had a plastic plug at some time. When I sealed mine up I noticed that this plug was missing. So I stuck a nut and bolt with washers in there to seal the hole. The hole was directly in front of the wiring harness entrance into the firewall and was probably a source of most of the water that was getting in.

I have not had a problem since I cleaned mine up with contact cleaner and sealed that wiring entrance with electrical and duct tape.

 

well my prob was unrelated to the block and harness. the wires were corodded at the prndl switch and bad prndl switch, so prob a good idea to check that as well. like I said harness and block dry/sealed up fine. the dealers charge a ton of labor. $650 to change a $230 part...they suck you in by charging a high diagnostic fee then wave it if you do the expensive repair. i prob could of done it myself, but getting lazy in my old age

 

Glad to see so many of you have found a good, inexpensive work-around. I still wouldn't fault the dealers. Dealer techs and managers can only do what corporate says. The reason for these extensive repair options (i.e. replacing the entire harness v/s contact cleaner and a little sealer) is for liability and insurance. Every manufacturer has to make sure that their liability is near or at zero. If they put sealer in it, and something failed, causing an accident, then they would be liable.(meaning the individual dealership doing the repair) Where if the full repair recommended by corporate were done, then the liability would fall on a corporate level, where they have deep pockets, and dozens of lawyers on retainer. It protects the dealership at the dealer level. No small dealership could handle a multi-million dollar lawsuit. Not to mention bad press. If I own a dealership, and I do a repair that the manufacturer said to do, then my press release is that I followed the manufacturer's recommendation, and therefore it was not our fault.

As for the information that many have supplied here, I say thumbs up and thank you for the info. You have probably saved many-a-tacoma owner lots of money for your hard work and dilligence. Thank you!

 

I had a remote start installed on my Tacoma when I purchased it 8 months ago. A few weeks ago my check engine light started coming on and the reverse to drive hesitation. I took it to the dealership and they want $2500 to replace complete wiring harness. Here's my question. If you do the non-dealership fix, how long does it take for the computer to "trash" the code? I can't get my truck inspected until the P0705 code no longer shows on the computer memory.

 

When I did mine the code went away as soon as i started the vehicle up without water crossing the wires. I could actually reach up under the driver side kick panel and feel water coming in following the wires down into the junction blocks.

 

sub'd

 

Well, where do I start?

I have the stiff shifter at times, also the hesitation when shifted into "D". I don't get this hesitation 100% of the time, but I get it maybe 40% of the time and its really driving me nuts. Along with the "D" hesitation, I have also noticed that my "P" indicator doesn't always illuminate when in park. Sometimes the "P" will illuminate faintly, flicker a little, and then either totally illuminate to full brightness or fade away to nothing.

The weird thing is I exhibit all these problems as the above posters, but I have no check engine light illuminated?? I had the truck on a diagnostic tool last night also and no current or stored codes in the ECU memory.

I suspect the neutral position switch is the culprit in my case, and plan to change that shortly. In the meantime however, I will pull my kickpanel and clean everything with contact cleaner and maybe add a little dielectric grease.

I would appreciate if the original posters in this topic would post a little update on how their repair has lasted - whether it be the expensive Toyota harness replacement or the DIY contact cleaner method. I would really appreciate an update from those involved if possible, even just a few words.

Thanks...

 

Sounds like you are having a different issue but since you asked for an update I'll post mine. Good look with fixing yours.

In my case it was definitely a water issue from two sources:
First one from going through high water, fixed by sealing the harness where it enters the cabin.
Second from a crappy installation of a replacement windshield. They didn't seal it all the way on the left side and so rain water got in and dripped down onto those connectors again. I went back there and they properly sealed it and I haven't seen any problems since.

 

Regarding Fortech's question. I had the issue three years ago and sealed the cable and cleaned the contacts and so far the repair has lasted with no issues. I did not have the error code for several months while I had the hesitation symptom but I finally got it. I do not know what sets the error code but the symptoms you describe seem related to the problem of the computer not getting the correct inputs to put the transmission in the proper mode. Good luck.

 

The code is set when the ECU gets two conflicting signals from the transmission switch at the same time. It would certainly be possible for a failure to occur that simply caused a lack of a signal, or the wrong signal, but not two at the same time. I could see how that may not set a code.

 

Mine is still going strong and the problem has not returned since I sealed up the entry into the cab and dried off the wires/cleaned them. When my truck exhibited the problem I could reach up into the wires and feel moisture coming through the firewall.

Another thing that I think contributed to mine getting water in on the wires was a missing plug in the driver side wheel well. I think water spray was coming up through that hole and potentially getting the wires wet etc.

 

I've noticed my shifter being pretty damn stiff to move into gear on the past few cold morning starts. Temps ranging from -25C up to a temperate -10C. After driving a little bit, the shifter moves as normal, so the transmission heating up must be freeing something else up.

When I started the truck tonight to leave work (-16C indicated), I only gave it about 30 seconds before throwing it into gear and heading across our skating rink...er...parking lot to a coworker's car to grab something. I did notice intermittent illumination of the shifter indicator in the instrument cluster. On the way across the rink, I was also fiddling with my rear diff lock (w/override) to kill my ABS and about the time I flicked the switch, I heard my UltraGauge warn of a pending code. I think the timing was just coincidence with the diff lock switch though.

Anyhow, the pending code was, surprise surprise, a P0705.

I cleared the code while the truck was idling in park (maybe it sat there running for 2 minutes?), shifted to drive without any resistance at all as well as no obvious issues with the shifter indicator, and didn't throw a code for the rest of my 80km drive home which included a gas stop and several runs through the shift pattern. I do downshift the AT, so there was plenty of opportunity to get two signals or whatever the situation is.

In my case, hopefully it's just the cold messing with the sensor. I've lubed the linkage every time I'm under there, so I don't think it's that.

It's a cold and windy night out there tonight, so we'll see how it behaves in the morning.

 

Only seeing a slight misbehaviour at very low temperatures, and a slight stiffness now. As soon as the tranny is warmed up though, we're 100% good.

No more codes either.

 

My 05 just came on with the 705 MIL. Im gonna follow the posts here and post my results.

 

I should follow up on mine. My shifter became sticky again this past year. The dealer did find the park neutral switch as the problem. I think the bill was in the $500 range for parts and labor to have them replace the park neutral switch and I have not had the problem since.

 

STICKY SHIFTER / SHIFTER IS HARD TO MOVE
Most of us would disconnect the shifter cable from the transmission lever and then verify the cable is free by hopping in the truck and moving the shifter from park to low . We should feel nothing because the shifter cable is no longer connected to the transmission . If the shifter is still tight to move , we know that the issue resides in the cable or the plastic shifter cover . A quick lube job is going to fix that up .

Next , with the shifter cable removed from the transmission lever , try and manually move that transmission lever by hand . You should feel click , click , click and it should be fairly easy to move with your hands . If you cant move it by hand , remove the PRNDL switch shown on page 16 at this link , it shows the switch in question . Spray the heck out of it . Some guys actually have to replace the PRNDL switch becuase of corrosion .The PRNDL switch gets very tight when it corrodes http://www.toyotatundraforum.com/pdf/A750E.pdf

When the switch is removed , you can spray the seal on the transmission that sits behind the switch to see if there are additional problems with the lever shaft since the lever shaft is also known to corrode .
, then take a small screwdriver and pry the lever seal away from the shifter selector shaft enough to blast some lubricant between the seal until you get the lever to move by hand .Might have to work it back and forth a little but its going to free up . You should have the wheels blocked when you do this .Both of these issues are very common

Next , place the transmission gear shifter in park and " REMOVE THE KEY "
Throw the key on the drivers seat until your done .
Go to rear of truck and manually push it by hand to verify the truck is actually in park . Go back under the truck and check to see if the shifter cable lines up perfectly with the hole in the transmission lever . If it doesnt line up , adjust the shifter cable until it fits perfectly into the transmission lever . The adjustment is under the shift counsole .
Once the cable is aligned with the transmission shift lever , verify the truck will only start in park and nuetral .

 

I'm in...
2014 TRD Sport with 1500 miles.
Ultragauge threw the P0705 pending code last night.

I'll read up and probably do a clear today and see what happens.