[Hippo393]

Last month I was troubleshooting a starting-relay issue, and a cigarette lighter socket that wasn't working. Worked on the starter relay, then the cig lighter. To get the front dash panel off, I had to shove a key into that keyhole to move the gear shift backwards to clear. Problem is/was, that when I buttoned everything up, and then tried to start the truck to test, the gear was thankfully in Neutral. Anyhow, both were fixed, but I immediately got the P1780 code, and it hasn't gone off (and it comes back soon after clearing the code).

Thoughts here on the likely culprit? What could I have fu-barred? I did search the forum here but couldn't find anything with a '97, as the 2000 model has the features discussed in the threads that I saw here.

Thanks gang!

-Alan
'97 4Runner V6, 352K miles

 

[sdspeed]

So the truck is starting and running fine but the CEL/code won't go away?
What's the battery voltage resting and when running?

 

[new echo owner]

Check and verify that the P/N switch is adjusted properly!

 

[Hippo393]

Thank you for the responses guys! I have not checked the voltage, as the truck seems to start and run fine, but the CEL notification P1780 won't go away, and keeps reappearing after I clear the code.

Tonight I located and cleaned off the Neutral Safety Switch on the passenger side of the tranny, and it is attached to this post. I searched on AutoZone's website, and they have 2 switches that they say fit my 4Runner, but they are $164 and $84 apiece. Seems like a big difference, and I'm not sure which one fits...if either.

Zooming on the pic of my existing Toyota brand switch below, it looks like the last 2 numbers on the red sticker are "22", but a google search didn't return any pics of a relevant Toyota part with those last numbers in them. Gah!

Also, new echo owner mentioned that I should check if the P/N switch is adjusted properly....how do I do that? The posts here and on YouTube show later models with dash lights

that aren't equipped on my '97 2WD.

-Alan

 

[Hippo393]

Did some research and ended up replacing the neutral safety switch. The trouble code P1780 returned right away. Gah!

Other thoughts in what could be the culprit?

Thanks gang!

 

[new echo owner]

Usuallyt P/N switch can easily be check by verifying the vehicle starts in Park and Neutral, and B/U lights come on when put into reverse, all indicators light up accordingly if equipped on the instrument cluster.
Anything else not working on the vehicle beside what you were fixing? Trailer harness?
There were also reference to IP and tailight issues causing P1780 to set!

 

[Hippo393]

Usuallyt P/N switch can easily be check by verifying the vehicle starts in Park and Neutral, and B/U lights come on when put into reverse, all indicators light up accordingly if equipped on the instrument cluster.
Anything else not working on the vehicle beside what you were fixing? Trailer harness?
There were also reference to IP and tailight issues causing P1780 to set!

The 4Runner did start in park and neutral, and the reverse lights do illuminate when in reverse gear.

The trailer harness has not worked in ~10 years, but has not been an issue since. I suppose that's a possible contributor to current issues, but how to explain why it hasn't been a problemo since? I dunno.

Looking back at that fateful day, I think what happened is that I must have forced started the truck whilst in some sort of gear, and not neutral. I do recall the feeling of "OMG, this beast could have run either through the garage door or the back wall" while force-starting it in gear (via hot-wiring the starting fuse socket). Replacing the neutral safety switch has not seemed to help.

Other thoughts, please?

Thanks!
-Alan in NC

 

[Hippo393]

Update: Problem solved! A couple weeks ago my fuel pump quit. Took me a while to troubleshoot, drop the tank, and replace the fuel pump. But after putting it all back together, with the first turn of the key, not only did it start, but the check-engine light never illuminated, and hasn't since. Hallelujah!

Thanks all!

-Alan