P1780 Code from ODB-II

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Land Speeder

Land Speeder

InstaH8R
Joined
Jul 23, 2004
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Snap! My new junk is a '96 and the CEL is lit... P1780 which indicates "A/T indicator switch" or "Park/Neutral Position Switch" Malfunction.
I've reset the CEL but it will come back after 14 miles...
Seriously, where do I start? Since my FSM is not in yet, where is this switch? I know it's on the trans, but where exactly? I've searched for 3 dang days and no one has shown exactly where it is.... only a VERY up close pic of the plug. How do I fix this CEL? My first guess is to check the connectors to ensure it's not gummed up...
Help a "newbie" out.
 
Land Speeder said:
Not really, cause it doesn't give a solution...
I've read those two posts roughly 50 times in the last 2 days.
Click to expand...

For the life of me I don't remember making that thread. I keep getting an intermittent check engine light that I really need to scan. By the time I think to scan it the light goes off and I forget about it.

I've always thought that my problem with the P1780 was due to my engine kill relay from the port installed alarm dieing on me. My windshield was leaky and water would leak onto this relay which then caused my truck to stop starting one day, i.e. a permanent kill switch.
 
96r50 said:
Passenger side, above the front driveshaft, in front of the ATF cooler piping. Pics here
:cheers:
Click to expand...

thanks, I've seen the pic, but didn't know the location since it's so "up close"



Darwood said:
For the life of me I don't remember making that thread. I keep getting an intermittent check engine light that I really need to scan. By the time I think to scan it the light goes off and I forget about it.

I've always thought that my problem with the P1780 was due to my engine kill relay from the port installed alarm dieing on me. My windshield was leaky and water would leak onto this relay which then caused my truck to stop starting one day, i.e. a permanent kill switch.
Click to expand...

Com'on man, think!:p crap, mine stays on and apparently has been on for years according to the two previous owners....
I have a LED light that indicates an alarm, but that's all I got, not remote nor do I find a box under the hood... where would the factory alarm be if in fact this could be causing my woes.
 
On a side note, I just installed the pioneer speakers that fit the front doors... I hoped that the sound would drown out the CEL.... but after the installtion I realized speakers only drown out sound! crap! Oh well, I got new speakers out of it!
I'm knocking out alot of things on this rig that had been ignored by the previous owners... I knew they were simple fixes, but this CEL debacle has stumped me! Aside from that, I just scored on a very sweet rig that just needed minor problems fixed.
 
Land Speeder said:
On a side note, I just installed the pioneer speakers that fit the front doors... I hoped that the sound would drown out the CEL.... but after the installtion I realized speakers only drown out sound! crap! Oh well, I got new speakers out of it!
I'm knocking out alot of things on this rig that had been ignored by the previous owners... I knew they were simple fixes, but this CEL debacle has stumped me! Aside from that, I just scored on a very sweet rig that just needed minor problems fixed.
Click to expand...


That thing is way too nice to have sold for what you paid for it. Now that you've got a new one and have to start from the ground up this will give me a chance to learn from a master........b8er:hillbilly:
 
Land Speeder said:
thanks, I've seen the pic, but didn't know the location since it's so "up close"
Click to expand...

The switch is on op of the transmission. From last I was looking around there, you can't actually see the switch, you can only feel it. That picture is taken from the side of the transmission, where the transmission shifter linkage connects to the transmission.

Land Speeder said:
Com'on man, think!:p crap, mine stays on and apparently has been on for years according to the two previous owners....
I have a LED light that indicates an alarm, but that's all I got, not remote nor do I find a box under the hood... where would the factory alarm be if in fact this could be causing my woes.
Click to expand...

Is the led in one of the switch knockouts and does it say Toyota on it? Also check under the drivers seat to see if the alarm module is there. If so you have the Toyota alarms (I think it's called the VIP 9000).

Here's the thread on my alarm issues: https://forum.ih8mud.com/80-series-tech/73390-80-wont-start.html

Forgot to add that I just checked my ECU and the code it threw was a P0133 which means I get to by new O2 sensors.
 
Last edited:
Anyone can help me here? Offer any more solutions to this mystery? Is the plastic clip considered the actual "switch"? Or what is the switch and can it be replaced? The clip looked clean. I can spray it with some DeoxIT Gold and scrub it if need be...
 
Land Speeder said:
thanks, I've seen the pic, but didn't know the location since it's so "up close"
Click to expand...

There are two more photos farther down the thread (just double checking that you saw them all!).

The switch is the part that the connector clips on to. Its about the size of a deck of cards. It has the control linkage from the tranmission shifter attached to a little arm which is mounted on the side of the switch. To replace the switch you would need to remove the nut, the little arm and possibly a washer or wave washer of some type. Then there is a second bolt that allows you to pivot the switch to align it with the correct positions in the transmission. The FSM explains it slightly better than I can :doh:
 
96r50 said:
There are two more photos farther down the thread (just double checking that you saw them all!).

The switch is the part that the connector clips on to. Its about the size of a deck of cards. It has the control linkage from the tranmission shifter attached to a little arm which is mounted on the side of the switch. To replace the switch you would need to remove the nut, the little arm and possibly a washer or wave washer of some type. Then there is a second bolt that allows you to pivot the switch to align it with the correct positions in the transmission. The FSM explains it slightly better than I can :doh:
Click to expand...

thanks for this info, it has corn fused me even further however. I understood the other pics to be of a 93, different trans than the A343.
Also, I saw the plug going into the shifter "bulb" but did not understand that to be the switch. I thought the switch couldn't be seen... dang I need that FSM, it still hasn't shipped, can someone PLEASE email me the pages needed from thier digital copy of the FSM?
 
Nope, TOY350 has a 95 with the same A343F as you and I. The switch does blend in with the transmission pretty well, but if you can get a flashlight in there you should be able to make out the difference. It would help if you could drop the front driveshaft. I don't think the NSS is a common problem with this transmission, but as you can see in TOY350's thread, he had trouble with a couple of the wire connectors (the ones for the starter). I had the exact same problem as him, and I believe Romer had it happen on one of his trucks too. So maybe your code is related to the one of the little wires in the plug and not the switch? Hope so, a new switch is pretty pricy :eek:
 
Thanks Adam, I hope it's just the wires too!
 
As the new owner of this truck - thanks Eric. I've figured it out. The 2 previous owners had a starting problem due to the Park/Nuetral switch gone bad, but to fix the starting problem a connector was placed on the PN-switch wires to by-pass it - thus causing not only the CEL code, but also disabling the Cruise control because it consistently thought it was in Park or Neutral. Here's the link to the thread/post I created and then updated with my findings... https://forum.ih8mud.com/80-series-...arts-any-gear-park-neutral-safety-switch.html Going to get that PN-Switch tomorrow and see if it solves all the problems...

Kind regards
Jack
 
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