I have a question about this code.
The thread about it from 04-20-2003, you can find it here.
https://www.f150online.com/forums/sh...hreadid=114011

I was having this driveline vibration more than a year ago.
There was no CEL, neither a flashing light on the gearlever.
The dealer where I bought my truck never could find a code.
I decided to pay a visit to the official ford service provider.
They found that code immediately when they hooked up the computer and ran the selftest.
I was surprised they found a code while others never could find one.
"Itīs probably because we are using the latest software from Ford", the Ford-tech said.
That same day we drove over to a European Ford models garage because he wanted to show me the WDS from Ford.
World Wide Diagnostic System.
They hooked up my truck, it was recognized but they never found that code again (P1780). Test was done by someone else.
That started to worry me a bit. Why find it on one computer and not on the other one.
Also, the Ford-tech over on the phone (FoMoCo transmission hotline) told this tech this code is very rare.
We had to check the overdrive switch on the truck.
The tech pulled one or other plug from the tranny.
That one was fine, tranny overdrive worked.
Switch was ok

*****
This is a quote from the original thread.
Posted by Mark Kovalsky.


[b[Self test is whem the scan tool is connected to the truck to retrieve the codes. You need to press the overdrive cancel switch during the engine running test or you will get a code P1780.


quote:
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My overdrive light never flashed. But my engine light came on while i was driving, its the first time my check engine light has ever came on , it set a code 1780.
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No, it did not. The P1780 code won't set when the truck is running. It set because whoever cecked the codes didn't run the test properly.[/b]

I donīt doubt his words, I just want a confirmation about this.

Didnīt the Ford Tech run the selftest correct.
The code P1780 will only show if you screw up the self test.
If so, that would be a bad thing, a Ford Tech not knowing how to run a test.

If he did know how to run a test, he deliberatly tried to fool me , finding a code for whatever reason. Codes have been pulled many times since then, never got that code again.
btw, the tech is pushing the switch and brake pedal during the test now.

Sorry about the long post.
Main question is: If you donīt run the selftest correct, you get a P1780 code.

 

F150Europe sez...

Yup. During the KOER (Key on, engine running) portion of an EEC test, you're to actuate certain inputs, usually the BOO, TCS, and PSP switches to verify that an output is being sent by those respective circuits. I forget to do them from time to time whenever I'm testing, sometimes it happens, but I also know why the code is there afterwards.

 

Thanks.

TCS means Transmission Control Switch

Where do BOO and PSP stand for.

 

BOO is the Brake On/Off switch, PSP is Power Steering Pressure switch.

 

So , to avoid this code you also have to turn the steeringwheel a bit, I guess.

 

Yes. The official instructions from the WDS when the test is in progress is something like, "Cycle TCC switch on/off, depress brake pedal and release, turn steering wheel 1/4 turn in either direction and release." The NGS just says to actuate applicable outputs (TCC, PSP, BOO).

 

Thanks