P0705 code popped on yesterday

Ok, I did it. Jumped the two wires (from what I think are two and three above) and turned the power on in my truck and 3 lights up on my dash. I didn't turn the truck all the way on.

 

Power is backfeeding. That is why I was saying turn the ignition on first, THEN jumper. You are not causing any damage, but you need key on to test that correctly.

 

Ok I did the test again this morning before work with the same results. 3 lit on my dash.

My exact steps were

1. Unplug park neutral switch
2. Get up and turn ignition on
3. Get back down and jump terminal 2 and 3
4. Got back up and the result was a lit 3 on my dash

Am I maybe not jumping the correct terminals?

 

Hmmm. I will recheck the wiring diagram. I was sure it showed 2 powered to 3 was for 2nd gear. I'll have to get back with you later.

 

Thanks Bill. Another symptom I am noticing (which I think has been happening just as long as the CE been on) is when I am on the freeway doing about 60-70, the transmission doesn't change to like 4th gear so my truck feels like it's driving in like 3rd gear and I have quite high RPMs. Around the city driving, I don't notice this.

 

Hey Ronnie . I am fairly certain that as long as the CEL light is on , your overdrive and lock up torque converter will be disabled . Its a fail safe to prevent any further damage .
When you get the Park Nuetral issue figured out and P0705 goes away , the ecm will once again tell the converter and overdrive to function as normal . Rite now , the ecm doesnt know what gear the truck is in

 

Well don't we all feel silly. lmao. I was looking at the wiring diagrams and such, instead of a search on the P0705 code! There are SIX bulletins on this code for US made trucks. All of them suggest checking this connector at the driver's kick panel for corrosion inside the connector.

 

^^^^^^^ I was reading that TSB earlier to see what fail safe provisons are made when the code trips but it doesnt say

 

Gotcha, that makes sense. Trucks going into the shop tomorrow for some fab work so I'll be out of a truck this week. I really want this issue figured out. I asked toyota how much to just tell me what is wrong and they want $110! I was like nvm I'll figure it out.

Bill, I read that bulletin when I originally got the CE light a few months ago. I checked that connector and it looks fine. I will check it again though and report back

 

OK , so you looked into that harness a while back and it was visibly fine . You jumped the two yellow wires and got 3rd gear to light up on the dash but # 2 still hasnt lit up .
So we are on the fence for a new park nuetral switch as a " guess " at this point .
Got any buddies at the wrecking yards near you ? I would love to see the park neutral switch swapped out at this point . They are going dirt cheap at the auto wreckers these days . If I was near you , I would pull the switch off my truck and try it on yours just for giggles lol .

 

Yeah I checked the wiring harness a few months ago and it was visibly fine. I checked it the first time the CE light came on.

Jumped the wire and got 3rd gear to light, but not 2nd.

I have a wrecking yard relatively close by but they all seem to be older cars. I have a friend with a 2nd gen tacoma that I'm sure would let me test his.

Man, now I wish my truck wasn't going into the shop tomorrow. It's going to be gone for about a week

 

OK, I have to make an apology. I was reading the wiring schematics wrong. I missed a line pass and went the wrong direction. Jumpering the two yellow wires is to turn on the "3" indicator. My bad. I was looking at the switch in the diagram incorrectly. To test the "2" indicator, and switch for that gear, you need to jumper terminal 2 (the larger of the two yellow wires) to terminal 8, the red wire with yellow stripe. Turn on the key, and shift the shifter into "2" position. The "2" should light up on the dash. Then shift the shifter down into "L" and the "1" should light up. If that does, then the selector switch on the side of the transmission is good. Sorry about that!

 

So I got the truck back from the shop on friday. I have hesitated on posting here yet, but so far no check engine light and 2nd gear is working again. I've driven about 100 miles on it so far.

The shop had the entire dash apart since I was getting cage work done so I am leaning towards a loose connection that was reseeded when they put the dash back together. They also had the battery disconnected for quite a while.

I will definitely report back here when and if this happens again and give your above response a go. Thanks Bama and gearcruncher for the help so far. Let's hope we don't have to revisit this thread for a while!

 

So the problem with delayed shifting is still happening. It only happens sometimes when going from [P]ark to [D]rive. I'll move the shifter to [D]rive and about 3-5 seconds later, the truck lunges forward and engages. I think it is becoming more frequent.

I still have no check engine light back on and my 2nd gear is still working as it should. I haven't really been able to find much information on the delayed shifting, other than the delayed shifting and my 2nd gear not working are somehow related.

 

Hey Ronnie .
Have you ever checked your transmission fluid .
When you say the truck lunges into forward , do you mean the transmission shifts hard ?
These transmissions have lunge prevention built in which means when you select forward , the transmission actually goes into second gear first and then it shifts into first . Toyota did this to prevent lunging . I would be interested to know if your trans is low on fluid
Got a bunch of information you can read here on how to check it
http://www.tacomaworld.com/forum/te...hift-kit-shift-recalibration-kit-2nd-gen.html

 

I have not checked my trans fluid. I had it changed out at like 70k miles from the dealership, but who knows what they actually did.

I suppose the transmission shifts hard into D. Moving the shifter into D isn't hard. Its when it actually engages is when the truck sort of lunges forward. It definitely doesn't feel right. I'll look into how to check the trans fluid since I know my generation of truck doesn't have a dipstick for this sort of thing.

How would low transmission fluid result in delayed shifting?

 

when a transmission is low on fluid , it takes a while for the transmission pump to supply oil to the clutch . When a transmission is filled properly , the transmission pump supplies oil to the clutch immediately

 

Sounds like you two are on the right track. I don't have anything personally to add, but I will try to keep my eyes on this thread.

 

Ok, that makes sense. I will figure out my trans fluid level later this week or weekend. I appreciate your help

edit: Ok, so quick search...since our trucks are a closed system as far as transmission fluid goes, there isn't really a way to check the level, is that right? I would have to do a full flush and refill.

Appreciate it

 

Here is how you check the fluid level

Fortech created an excellent write up on how to properly check the fluid at home . If you are interested to see if your truck is low , click the link below
http://www.tacomaworld.com/forum/2nd...nsmission.html

Here is the PDF from Toyota showing how to fill / check the fluid . Scroll down to page 18 for the details http://www.toyotatundraforum.com/pdf/A750E.pdf

And then read here http://www.purefjcruiser.com/docs/20...d/01600210.pdf