Ck Eng Light P1780 - Toyota Nation Forum : Toyota Car and Truck Forums

winarth · 02-21-2008, 06:25 PM

My son's 97 Camry had a check engine light on and the mechanic replaced the transmission neutral safety switch. The light came on again after 2 days. The mechanic now says the bad switch probably messed up the computer and it has to be reprogrammed or updated. If that doesn't work, it will have to have a new computer. He says there is continuity between the computer and switch. The code is P1780.

Having spent just over $400 so far, the cost of updating the computer ($2-300)seems stiff. I know what a new computer costs, I just want to know if all this seems reasonable.

Luckynumber5 · 02-21-2008, 06:39 PM

there is no reason to replace a Toyota ECU, more than likely you have a bad ground somewhere or the code is a result of something else. You need to take it to someone who will not charge you to pull the code and read the possible causes (most auto parts stores will do this for free), then think about spending more money on the problem. It could end up a lot cheaper than just replacing parts.

digmycelica · 02-21-2008, 11:21 PM

Quote:

Originally Posted by winarth

My son's 97 Camry had a check engine light on and the mechanic replaced the transmission neutral safety switch. The light came on again after 2 days. The mechanic now says the bad switch probably messed up the computer and it has to be reprogrammed or updated. If that doesn't work, it will have to have a new computer. He says there is continuity between the computer and switch. The code is P1780.

Having spent just over $400 so far, the cost of updating the computer ($2-300)seems stiff. I know what a new computer costs, I just want to know if all this seems reasonable.

It is possible this is true.
It's either a short in the neutral safety switch circuit. A bad neutral safety switch or a bad ecm .

csaxon · 02-22-2008, 10:40 AM

Check the electrical connection at the neutral safety switch, it may be corroded and need cleaning,etc.

ShawnM · 02-22-2008, 11:24 AM

Nine times out of ten that code is set due to a pinched or broken wire going from the neutral safety switch to the rear tail lights/back up lights. Check the wiring harness in the trunk where it flexes when you pop the trunk open. I bet you'll find at least 1 damaged wire. Reprogramming the ECM will not fix anything.

winarth · 02-23-2008, 11:58 AM

You are absolutely right! Thanbk you. A broken ground wire fixed the problem. Now, what do I do about the mechanic and the sunk costs--probably nothing....

Luckynumber5 · 02-23-2008, 03:05 PM

Put it behind you and make sure it never happens again. Money is time, and you can't get either back. These message boards are usually 24/7 so come back if you ever feel like you are being pushed around by a mechanic

ShawnM · 02-23-2008, 05:21 PM

We'll push you around but wont charge you for it.

digmycelica · 02-23-2008, 10:10 PM

Quote:

Originally Posted by winarth

You are absolutely right! Thanbk you. A broken ground wire fixed the problem. Now, what do I do about the mechanic and the sunk costs--probably nothing....

Where was the broken wire, was it in the trunk?

nuron · 07-03-2008, 01:59 AM

I just got this code also and my reverse lights aren't working. Was the ground wire in the trunk?

nuron · 07-06-2008, 01:11 AM

Turned out to be some broken wires near the trunk loom like usual. Spliced them with some wires hanging so there's a bit of slack when the trunk is extende. Hope the smaller gauge keeps working!

Mike Gerber · 07-06-2008, 12:34 PM

Quote:

Originally Posted by nuron

Turned out to be some broken wires near the trunk loom like usual. Spliced them with some wires hanging so there's a bit of slack when the trunk is extende. Hope the smaller gauge keeps working!

I would get a spool of the same gage wire and splice that in. Using smaller gage wiring than the system was designed for is just not worth the risk, IMHO. A bit of the correct gage wiring is cheap insurance.

Mike

Jon Ondich · 11-11-2008, 12:14 PM

Quote:

Originally Posted by nuron

Turned out to be some broken wires near the trunk loom like usual. Spliced them with some wires hanging so there's a bit of slack when the trunk is extende. Hope the smaller gauge keeps working!

How did you find the broken wire? was it obvious? Was the wire in the group by the back hinge?

I am getting the same code. For years I have had problems with back tale lights. The only error I would receive was the lights warning on the dash. Now I am getting the check engine light too.

Mike Gerber · 11-11-2008, 03:16 PM

"The only error I would receive was the lights warning on the dash. Now I am getting the check engine light too."

These two things may or may not be related. Get the code(s) read. If your car is a 96 or newer, it is OBD2 and you can get the code read for free at Autozone, along with other parts stores. If you don't have Autozone in your area, make a few phone calls to other auto parts stores in your area and ask if they offer this free service. Then post back here with the code(s) and someone should be able to give you some direction. If your's is a different code, I would suggest starting your own thread with a proper title based on the code.

Good luck.

Mike

Jon Ondich · 11-12-2008, 07:58 AM

I added to the old post because it is quite revelent to my problem. I am receiving code P1780 which is the Park/Neutral position switch.

I played with the wires last night. I could not see anything - just wiggled them arround. This morning the check engine light is off. However, the "lights" warning on the dash is still on.