Hi everyone.
I own a 4runner (1997 V6 4x4 A/T SR5) for the last 3 years. Never had a problem.
Recently it threw me a p1780 code. I was backing up and then stopped completely and engage the "D" and pull forward about 10 feet and the check light came on.

Turns out to be park neutral switch. I reset the ECU (removed the ground wire).
Started the truck and select gears = no check engine light
Turned off the engine and started again and went through the gears and there goes, light is on again.

Tried two used park safety switches (reset the ECU every time) and still have no luck.
I tried adjusting it and same results.

Both back up lights are working fine.

I also see the gas indicator comes down when the check light is on (with a full tank of gas, it shows 3/4 full).

IS this because bad:
ECU? Back up light short circuit?
Please help.

It's your username--your Toyota doesn't like you hanging on to a Nissan like that! Seriously, I'm afraid I have no idea on your issue, but welcome to the forum. There is likely someone on here that can help you--have you also posted this in the 3rd Gen section? That's where it'll do the most good. Best of luck!

My name is Nissan but drives Toyota.
Other than removing the negative terminal, is there any other way to reset the ECU?
I am good at things, I opened the Safety Neutral switch and cleaned all the contacts and tracked down the contacts. After assembling all back together I checked the contacts and all have perfect contacts.

No broken wires at the connector as well.

I have an ECU, should I simply replace it and see?
Any advice?

I hate these electrically driven cars. Where I am originally from, we have Hilux 4wd Diesel. All it needs is Diesel, motor oil and a good battery to go. This is the reason why there are less members in the hilux forum.

Thanks

Its interesting the fuel gauge is affected with a shifting input, take a look at this tread, 2000 4runner SES: P1780 - Toyota Nation Forum : Toyota Car and Truck Forums

Good Luck

Hi,

My 4runner don't have the PRND indicator in the dash cluster. Anyways, I checked what stated in the thread and nothing happened.

After cleaning inside the N/P safety switch and the contact points at the wire plug, the fuel indicator started working fine.

Recently I installed front day time driving lamps (all new wiring with fuse and relay, not connected to the original wiring) however I took a signal from the starter solenoid wire to disconnect the driving lamps only when the starter is engaged. Then again, I had no problem for about 2-3 weeks. Can this be the cause?

If this check engine light does not affect the rest of the functions in my truck, I'll use it just as it is.

Any other suggestions? Does anyone suggest me to take this to the dealership?

Good morning everyone.

I found the problem. I have taken a pulse (12V signal) from the starter wire to shut down the accessory lights (day time running lights) at the time of crank-up. I used a relay (Nissan) that opens when it gets 12V. [This method worked perfect for my 92 Toyota Sprinter (Geo Prizm! in the US) which also has day time running lights].

I removed the pulse coming from the starer and bamm..... NO MORE CHECK ENGINE LIGHTS!

So did that fix the p1780 or just the check engine light?