View Full Version : 2000 Toyota Camry

Grove Knoxville
12-18-2010, 11:44 PM
I have a trouble code P1780, which is a "Defective Park/Neutral Switch, an open or short in the Park/Neutral switch circuit or PCM malfunction" refer to page 7B-11 of the Haynes Manual for 2000 Camry. The car is a 4 cylinder SE with automatic transaxle.

I changed the Park/Neutral Switch, when I checked the Ohms on the new switch, the continuity matched the radings in table 5.4b (which is the V6 model on page 7B-4). I was expecting the continuity to match the readings in table 5.4a. I returned the Park/Neutral Switch purchased on-line (assuming it was defective) and purchased a brand new Park Neutral Switch from the local Toyota dealership and observed the same readings as table 5.4b. I have concluded the book is incorrect.

The issue now is the P1780 code returns after it is cleared. Two additional sypmtoms that I cannot run down: 1) When I depress the brake pedal the "reverse indicator light" on the dash board lights up everytime the brake pedal is depressed. 2) the back-up lights do not work and there is a "yellow light indicator" idiot light on the dash that is on, I checked the 10 amp gauge fuse and it is o.k.

There is a reference on page 7A-2 in table 4.2 to a back-up light switch on the top of the transaxle. However, this is in the section on manual transaxles and I do not find this switch on the automatic transaxle. Is this switch just for the manual transaxle? I have studied teh wiring diagram on page 12-37, it looks like the circuit goes through the 10A gauge fuse and the Park Neutral Switch.

I have also changed the bulbs in the back-up lights and so I am not certain what to check next.

12-20-2010, 11:06 PM
Hello Grove Knoxville,

We'll look into our tables (5.4a and b). Does the vehicle seem to operate normally apart from the symtoms that you have described? We may have to see about getting vehicle specific wiring diagrams to you to help you with your diagnosis... Have you performed a shift cable adjustment after adjusting the switch?

Email one of our tech service reps at research@haynes.com, or call them at 1-800-442-9637. Give them the number/letter combination on the title page of the manual, just to the right of the Haynes logo; it looks something like this: (4JR - 36055). They'll do what they can to help with the diagrams.