Toyota Nation Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I am new here.

My question is about a Toyota Camry 1998 make, which has over 140 k miles on it. It has a constant problem of Check engine light that comes up intermittently with P1780 code for the last 10 years. I took it to the dealership and changed park neutral switch couple of times and some other troubleshooting but the check engine light keeps coming back with the same p1780.
I couldn't find a mechanic who can resolve the problem. Any suggestions for troubleshooting? I am able to clear SMOG check every year but this intermittent problem keeps coming back. Thanks in advance!
 

·
Almost 1/2 Million Miles!
Joined
·
1,758 Posts
Yes! I have the same issue!

It is no wonder my dash instrument cluster illuminates the R (reverse) when in any gear when the lights are ON! I believe it denotes that something is very wrong at my back-up lights!
 

·
Registered
Joined
·
3 Posts
Discussion Starter #4
Do your backup lights work? Check the wires in the trunk, drivers side hinge area. Could be broken wires.
Thanks for the suggestion. Yes, the backup light works. On a cursory glance, I don't see any wires broken. How do I check if the wires are having problems? Sometimes when I pull wires, the check engine light with P1780 code clears off and then comes again. Most of the time check engine light and same code comes on when I switch to reverse gear to back up my car.
 

·
short-throw dipstick
Joined
·
5,916 Posts
+1 on patcal. I had a '97 4Runner in with the same issues, and a few other weird ones: turn signals would hyperblink when pressing the brake pedal. The owner tried to install a backup camera that came with his head unit, messed up the hatch wiring, and ended up with a short to ground. Check all wiring, P1780 is almost NEVER a bad NSS.
 

·
Almost 1/2 Million Miles!
Joined
·
1,758 Posts
+1 on patcal. I had a '97 4Runner in with the same issues, and a few other weird ones: turn signals would hyperblink when pressing the brake pedal. The owner tried to install a backup camera that came with his head unit, messed up the hatch wiring, and ended up with a short to ground. Check all wiring, P1780 is almost NEVER a bad NSS.
Yes, it certainly is not a NSS problem but, it sure affects it depending on the Electrical Issue (Short or Floating Ground) from broken wires somewhere!

 

·
Registered
Joined
·
3 Posts
Discussion Starter #7
Yes, it certainly is not a NSS problem but, it sure affects it depending on the Electrical Issue (Short or Floating Ground) from broken wires somewhere!

Thank you for the generous suggestions.
I tried opening up the hood to glance wires, where do I start?

I have a multimeter - to check continuity - any weblinks or youtube videos or will repair manual such as CHILTON help?

I tried calling a couple of local repair shops, most of them don't have electricians and asking for unlimited budget
 

·
Almost 1/2 Million Miles!
Joined
·
1,758 Posts
So Sorry, we all have our limitations and if you don't know how to troubleshoot using Electrical / Electronic tools then, try to get a friend that knows, in case your budget doesn't allow to take to a shop.

Best of luck!
 
1 - 8 of 8 Posts
Top