P1780 2000 toyota camry le

Hi, I got the pleasure of working on my step fathers car and I pulled up dtc p1780 with my scanner so assumed it was the park /neutral sw. so 229 dollars later I have the same problem. Heres where it gets interesting Everything works correctly according to my scanner until I push down on the brake and the scanners is saying reverse is engaged.The light on the dash comes on saying its in reverse. I'm Leaning towards the ecu now????? dont want to spend alot of money on another part and not fix it. any help would be great. thanks,Jim V

Do you have the same problem without the scanner hooked up?

Yes the problem is still there when the scanner is not hooked up.I even disconnected the park neutral switch and step on the brake and the reverse light comes on when its in P N D 2 L.

Yes the problem is still there when the scanner is not hooked up.I even disconnected the park neutral switch and step on the brake and the reverse light comes on when its in P N D 2 L.

I would think park/neutral switch would be a safety switch to prevent starting the vehicle other than in park and neutral. Does the vehicle also have a reverse light back up switch or is it all combined into the switch you are talking about?

I proped a flash light on the brake and the revese lights on the back of the vehicle dont come on but the light in the instrument cluster is on and the scanner is saying reverse is engaged while your in any gear with your foot on the brake pedal.

"I proped a flash light on the brake and the revese lights on the back of the vehicle dont come on but the light in the instrument cluster is on and the scanner is saying reverse is engaged while your in any gear with your foot on the brake pedal."

It is always helpful to list the year of the car, which engine, how many miles are currently on the car and what if any maintenance has been done to the car recently.

That said, it is common on all Camrys to have problems with the loom of wires inside the trunk, attached to the driver's side trunk hinge. That loom is subjected to a lot of flexing, each time the trunk opens and closes. Eventually some of the wires inside that loom fray and break. I would start looking for a problem there. Open that loom of wires and look for frayed or broken wires. Repair what you find.

Mike

I found the problem Yesterday!!! Before I read mikes answer but you where dead on right. Three wires in the trunk hinge area shorted together on being the ground the brake and the reverse light circuit.Needless to say when I pushed on the brake it energized the reverse light on the instr. cluster and telling the ecm that the shifterwas in rev. I eliminated the ecm because I had the ecm totally disconneted and still had the problem so I knew it had to be wiring and I remember my step father saying he was having problems with his lights on his trunk Duhhhhhhh!!! thats when it hit me. Thanks for the help Hope this will Help someone else because I was pulling my hair out and its getting thinner everyday.

Hello All,

I had a similar experience with my mom's 2000 Camry LE. 3.0L V6 with 131,000 miles, automatic transmission. The symptoms were as follows:

1. Check Engine was lit on the dashboard panel. ODBII code of P1780.

2. The R (reverse light) on the dashboard would light up each time you hit the brake and go away when you released the pedal (in all gears except Park or Reverse).

3. Dashboard panel also had a lit symbol of the vehicle that indicated that something was wrong with the rear lights (the symbol actually did not appear until you press on the brakes after starting the car each time and stayed on until you turned off the car). The rear lights were functioning properly.

4. Whenever you brake after driving at least 30 MPH, the car would shudder just before coming to a full stop.

Had all the brake pads changed on all 4 wheels just 4 days before this all started. Took the car back to the mechanic who found the same code of P1780. He stated that the problem was with the tranny. He said two valves were stuck open and that they caused this code. Report from mechanic said that the tranny fluid was burnt and needed to be flushed and replaced.

I did some research myself and found this forum and your guys post. This led me into the right direction. My brother is a smog technician and together we checked the wiring harness in the trunk but did not find any frayed wires. We then physically inspected the rear brake bulbs (remember that they were functioning properly). On the passenger side bulb, we noticed a black hue to the bulb similar to how a burned out bulb looks.

On a whim, we swapped out this bulb and voila, the check engine light disappeared. I turned off the engine and restarted the car and the symbol for a problem with the rear lights did not come on when I pressed on the brake pedal and the check engine remained off.

We took the car for a drive and the shudder was gone. My brother summized that the bulb was causing the P1780 code perhaps because of a drop in resistance and the ECM interpretted this incorrectly.

So thank you all for posting. I hope that this helps someone else with this issue.

Hello All,

I had a similar experience with my mom's 2000 Camry LE. 3.0L V6 with 131,000 miles, automatic transmission. The symptoms were as follows:

1. Check Engine was lit on the dashboard panel. ODBII code of P1780.

2. The R (reverse light) on the dashboard would light up each time you hit the brake and go away when you released the pedal (in all gears except Park or Reverse).

3. Dashboard panel also had a lit symbol of the vehicle that indicated that something was wrong with the rear lights (the symbol actually did not appear until you press on the brakes after starting the car each time and stayed on until you turned off the car). The rear lights were functioning properly.

4. Whenever you brake after driving at least 30 MPH, the car would shudder just before coming to a full stop.

Had all the brake pads changed on all 4 wheels just 4 days before this all started. Took the car back to the mechanic who found the same code of P1780. He stated that the problem was with the tranny. He said two valves were stuck open and that they caused this code. Report from mechanic said that the tranny fluid was burnt and needed to be flushed and replaced.

I did some research myself and found this forum and your guys post. This led me into the right direction. My brother is a smog technician and together we checked the wiring harness in the trunk but did not find any frayed wires. We then physically inspected the rear brake bulbs (remember that they were functioning properly). On the passenger side bulb, we noticed a black hue to the bulb similar to how a burned out bulb looks.

On a whim, we swapped out this bulb and voila, the check engine light disappeared. I turned off the engine and restarted the car and the symbol for a problem with the rear lights did not come on when I pressed on the brake pedal and the check engine remained off.

We took the car for a drive and the shudder was gone. My brother summized that the bulb was causing the P1780 code perhaps because of a drop in resistance and the ECM interpretted this incorrectly.

So thank you all for posting. I hope that this helps someone else with this issue.

Is that crazy or what.:screwy: A defective light bulb was to blame for all that havoc. :shakehead Congrats on fixing the problem.

Regards,
JOET/CAMRY

Great thread with helpful information. Thanks guys

sorry to bring an old thread back to life, but i am currently having this problem.

i noticed that one of my rear brake lights was burnt so i went to the local kragen store and bought light replacements for both my rear brake lights and reverse lights.

upon replacing all four lights my 'check engine light' went away but i was STILL having the issue of the reverse light on the dashboard turning on when pressing on the brakes.

now, i haven't checked to see of obd-II would give me the p1780 trouble code but i called my local toyota service center and they quoted my ~$500 for both parts and labor on a 'Park/Neutral Position Switch Malfunction.'

i cannot afford a ~$500 repair as i am a starving college student, but ANY advices would be greatly appreciated.

I can give you the same advice I gave originally on this thread. Open up the loom of wires inside the trunk, by the driver's side trunk hinge, and look for frayed or broken wires. Repair what you find.

Mike

hey all,

i just wanted to give an update on my status. i went to my local auto shop and they took care of the P1780 error.

as mike suggested, my mechanic checked inside the loom in the trunk and found majority of the wires connecting to the brake, reverse, and taillights frayed. it was due to the normal wear and tear as expected.

we patched it up, resetted the check engine light and everything was back to normal. the reverse light on dash stopped appearing, rear lights indicator disappeared, and engine stopped shuddering before coming to a full stop.

here are some photos from the repair:
http://www.automotiveforums.com/vbulletin/attachment.php?attachmentid=39056&stc=1&d=1272326728

http://www.automotiveforums.com/vbulletin/attachment.php?attachmentid=39057&stc=1&d=1272326748

http://www.automotiveforums.com/vbulletin/attachment.php?attachmentid=39058&stc=1&d=1272326748

thanks again to everyone for contributing. i just saved ~$500 worth of repairs.

(=

-dcskyline

Placed wire fix into FAQ thread under DTC P1780 fix.

Thanks Mike

Thanks Mike!

Had the EXACT same problem on a 2000 Camry XLE... ATTN readers: Don't let a Toyota dealer service department tell you your transmission needs work until you check your wiring in the trunk. A quick fix (and cheap $.38 worth of wire) fixed this problem.

Saved me both a headache and some $$$. I can't thank you enough!

jason

jason,

You're welcome.

Mike

thank you for this thread. I had the problems describe in this thread and it was the wiring near the hinge.

I followed the instructions on this thread and the problem was resolved. I knew that there was an easy fix on the web, thanks to all of you who contributed.

My introduction to this forum is too late to have possibly saved money. I too had the conditions covered above and since we were approaching Christmas I pacicked and went to a dealer. They changed the neutral safety switch for about $550. After reading the posts I checked the wiring and found no problems. I did find indications that they checked the loom. I could not tell if they changed any lights in the trunk lid. Maybe it was the switch. By the way I have 243,000 miles on the car and other than regular servicing I have only spent a few hundred dollars on the emission system.

Thanks, I was able to fix my car. My car actually had the reverse lights on the tail of the car and the R light on the dash lit all the time (pressing the brake or not pressing the brake). I also had to change the fuse since I blew it during the wiring fix outlined in this thread. My Camry is a 1997 xle with 103K miles (btw few very good mechanics thought this was a transmission issue when they saw the symptoms)

I ran into a somewhat related issue with my 99 Camry. When I applied the brakes the brake dash light would light. After finding a burned out bulb I replaced it but still got the dash light. I checked the wire loom, (it appeared OK), and searched the forum and found a post (cant find it again) that recommended replacing light bulbs in pairs as different bulbs may offer different resistance and thus trigger the dash light. After replacing the other brake light with the same as the new replacement the dash light issue was fixed.

1999 Toyota Camry P1780 failed inspection:
I just registered to this site specifically to say THANK YOU for this post. I failed my MA inspection yesterday (as anticipated, because my dashboard was lit up like a Christmas tree). I anticipated having to pay hundreds of dollars, but then decided to google my car issues:
-Check Engine light on
-Rear lights light on
-Brake light on
-Reverse light on (when the headlights were on)
-License plate lights out
-Back-up lights out

With the car running great, my mechanic had said that the check engine light problem was around the transmission and he'd have to start digging (translate: cost lots of money). Armed with this post after searching the P1780 code, I went into my mechanic and confidently told him to start at the wire loom in the trunk, replace the bulbs, and see where we stood before charging me any more money. Only $188 dollars later, I passed my inspection with flying colors! Definitely would have spent more money without you guys, so, thanks a million. Hope that this post helps other 1999 camry owners, too!

Same problem here--2001 Camry LE, 135K miles, failed the smog check. After spending $260 to make repairs for 2 other codes that came up, the check engine light was still on, and the P1780 was the code that came up.
My back-up lights weren't working, the light out indicator was on, and the R light came on every time I hit the brake. My brilliant wife decided to google the code, and found this forum. We printed it out for the mechanic and asked him to check out the wiring. Sure enough, 3 burned wires in the trunk harness. Forty bucks later, he fixed the wires, all of the back lights on the car work, no more check engine light, no more code, passed the smog check. Much better than paying hundreds of dollars to fix a transmission switch. Now our mechanic knows, and I hope others find this information as well. Big thanks to automotiveforums.com!