Posting this up in regards to my parents 2000 4runner (2wd, 3.4)

Got a call from my parents tonight about an issue with their 4runner (the check engine light came on Saturday). They were coming up a hill tonight when the engine revs and loses power (kind of felt like it slip out of gear) for a moment and then regains power.

When it regains power the reverse indicator light on the dash goes on despite the car being in the drive (the drive light is lite up). Even with the car in park the reverse light still remains on.

Is there a fuse/switch, sensor that would cause the reverse light to go despite the car being in a different gear? How would lossing power then regaining power factor into it?

Hopefully, this makes sense and I will be searching the various threads for a possible answer as well but any direction you all could give would be great .

I'd find out what the CEL is. Possibly a solenoid issue. Have them check the fluid also for level and color.

Anyone know how to replace the "Park Netural Switch"??

They pulled the code and it indicated an issue with this switch.

Smallfry, did you ever find out what the problem was? If so, how did you fix it?

I know it's been awhile since you posted, but I am having the same issue with my 2000 4Runner.

I took it to my Toyota dealer and they had a master mechanic look at it over 2 days. He still could not find what the problem was indicating that it "requires extensive diagnostics and tear down" and $$$. He said that even though the check engine error code indicated a "park/neutral position switch malfunction", that that switch was not bad and the problem is likely an intermittent short/grounding issue somewhere and very difficult to find.

Anything?

October 13, 2015
I finally figured out the solution to this problem thanks to smallfry and some other research. The problem is the blue flexible circuit board on the back of the instrument cluster unit. The board was corroded and shorting things out causing all sorts of weird problems. I tested some of the circuits on the board with my multi-meter, but was never able to confirm a short. I found some other blogs where guys had very similar problems and said replacing the board fixed it. For about $50 I figured it was worth a shot.

I have a 2000 4Runner SR5 (not Limited) automatic 6 cylinder (5VZ-FE engine) with 197K miles. The CIRCUIT BOARD part is 83861-3D260 for $51.36 online. I was getting a P1780 code that pointed to the park neutral switch, but that was fine (the Toyota tech tested it). Here are more of the symptoms I was seeing:

- Check engine light was on. Getting P1780 code.
- The reverse “R” indicator light was dimly lit when the headlights were off and the truck was not in reverse.
- The “R” would brighten some when the headlights were on and it was not in reverse.
- When driving and the high-beams were switched on, the truck would rev higher and seemingly lose power. What was actually happening was the truck was shifting down into first gear (really weird, but the Toyota tech confirmed it).

Other people have also reported other strange things with the instrument panel lights. One other thing is that this is an easy job. Removing the instrument panel is pretty simple and fast. Just remove the bottom panel below the steering wheel (4 10mm bolts), pop off the small plate that surrounds the key hole, remove the instrument panel cover (4 screws). I popped off the dash light dimmer knob and the little alarm unit so I could remove the instrument panel cover and clean it up. Then there are 2 screws that hold in the instrument panel. Remove those and unplug the wires on the back. That’s it.

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Great post. Thanks for the followup

Thank you so much for this! I just purchased a 1999 3.4 limited 2wd with the same prob. High beams=downshift and power loss. So crazy! So th e board replacement solved the problem correct?

Ok, I was having this weird shifting all of a sudden and couldn't figure out how it was happening. I just realized what was making it happen! If I put my left turn signal on or right turn signal on, that's what causes it to upshift and get confused with the gears! but only when I put the turn signals on... I have a '97 limited. I just pulled out my gauge cluster and will attach pics. BUt how do I know if it's that board that's bad? Another thing, if I drive without the gauge cluster OUT for a short drive and put my signal on and it doesn't do the crazy shifting, then we know it's that board 100%? The signal makes it do it every time normally.

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Other side.

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Wow, what a crazy one!

Based on your tests, it is definitely something with the gauge cluster. Check all those traces really carefully...

Especially the wires from the section of the cluster with the gear indicators and the turn signal bulbs (anywhere those traces get close to each other).

Good luck!

You probably can get a replacement cluster and just swap in your speedo/odometer...

-Charlie

Since i have a '97, I don't have any of those gear indicators. Those were only added on 98+ models....

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But you have the LEDs over on the tach, right? If so, it can do the same thing, probably...



-Charlie

Nope, I do not... only 96-97 are this way, then 98+ I think added those indicators on left... Edited my posted above to show pic of other side. Then on 99+ indicators on the right side. They must have made a change for later years. BUT, 96-97, NO indicators anywhere except on shifter console.

Video of issue:

http://www.youtube.com/watch?v=40fAGOfDr38

EDIT!!!!



It was the 3rd brake light! This bulb being burnt out made my truck shift erratically (triggers torque converter lockup) when puttin the turn signals on in the final drive gear at highway speeds. If this bulb burns out, beware of this.

I’m having a similar problem, but a replacement cluster did not resolve the issue. I think I may have a short in the harness.

Video of dash
99 4Runner Automatic transmission dash indicator light issue - YouTube

Yes hello. I'm having this issue as well on my 2004 limited v6 4wd and took it to my trusted mechanic and ran a possible issue with the automatic transmission gear positioning sensor. I haven't replaced it yet because I want to be sure I get the right part to fix the car.
When I turn on my lights while its stopped, it stays what seems to be first and when I turn on the lights while driving it drops a gear like shutting off overdrive. It doesn't return to the proper gear until I turn off the lights. Also the VSC trac lights are on and "off"