This might be a dumb question to some, but if I am getting a p401 could it eventually cause the cruise control to stop working?

I also just got the cruise control recall done about 2 months ago and my cruise went out about a month after that. I've had the code for a few months before that. I'm just wondering if it has to do with the recall done or the code or something completely different.

Thanks for your replies!

 

The cruise going out could be a blown fuse in the new harness.
to test the cruise control :
The P0401 DTC, do a search on it, there are 350 threads with P0401. The 4.6 is known for clogged EGR ports. Good thread on the topic ( still do the search )
https://www.f150online.com/forums/en...ode-po401.html

 

Thanks! Yeah I've done the search for the 401 code. I was just wondering if it could have anything to do with the cruise control issue. I will try the test when I get home.

 

One more thing. When I try to turn it on, I press the on button and then the set button and the cruise control light will flash on and then immediately back off.

 

I tried this on mine and the light didn't even come on, any ideas? 2004 F-150 supercrew 4x4.

 

Well I haven't tried the self test yet, but I finally called the dealer to schedule an appointment and they said there is no way it could be the new harness and they were going to charge $77.50 just to check it out. Are they just bs-ing me or could it be the recall harness?

 

Just had 2 other threads, where the dealer the member used, claimed the recalled harness had caused a problem.

I guess it depends if you have a 1st gen or 2nd gen recall harness

 

They want $77.50 just to check it and probably not tell me if it was the harness since they said there is no way it could be.

 

Run the self test, and see what happens.

The 2nd gen harness has an ATM fuse in the side of it, that if there is a condition ( like leaking ) that causes a short to ground, this will blow. You can check with a meter from the end of the connector, to the far side of the fuse ( little metal pins in the back of it ).

 

I finally ran the self-test last night and it blinked after every button and when I hit set/accel, it flashed 3 times. What does that mean?

 

3 flashes - deactivator switch is open or circuit defective.

Okay I found what 3 flashes mean, but what does this mean?

 

So what do I need to do?

 

switch or harness or both or just a fuse in the harness?

 

Sorry, yesterday was busy as all get out, just got back to this today.

The test for to find out what needs to be replaced, requires 1 more step.

Measure the voltage between the speed control servo C122 pin 9, circuit 307 (BK/YE), harness side and the speed control servo C122 pin 10, circuit 57 (BK), harness side.

If the voltage greater than 10 v, then install a new speed control servo.

If the voltage is less then 10 v( i.e. 0 v ) :
Measure the voltage between the deactivator switch C1025, circuit 10 (LG/RD), harness side and ground, for voltage greater than 10 V.

If no, there is a problem with the circuit ( which could be the ATM fuse in the harness ).

If yes:
Measure the resistance between the speed control servo C122 pin 9, circuit 307 (BK/YE), harness side and the deactivator switch C1025, circuit 307 (BK/YE), harness side for resistance less than 5 ohms.

If the resistance is less than 5 ohms, a new deactivator switch is needed.
If the resistance is greater than 5 ohms, there is a problem with the circuit ( again could be the ATM fuse in the recall harness).