I have had a number of motorcycles that the gauge pointers would sweep when the ignition was turned on. I always wait for them to complete the sweep before starting. I had a diesel F250 and would wait for the glow plug light to go out before starting so the sweep was always done before starting.
Now with my recently purchased 2010, when I cycle the key to the on position, there is quite a delay before the gauges sweep. I haven't looked in the manual ( I know I should) but do you wait for the sweep or just start immediately?

 

I don't wait

 

Go ahead and start. The gauges will sweep regardless

 

You don't need to wait for the gauges to sweep. FWIW the 09s don't even perform the gauge sweep.

 

OK, I guess I will just let it rip!

 

Whats the purpose of the sweep?

 

I believe that the sweep is part of the computer startup self check. I usually just turn the key to run. I don't yank it into gear until it's done though.

 

Has it always done this? If not, it might be a sign of a low battery.

- NCSU

 

NCSU, it does it every time you put the key in the run position.

 

It does it everytime on my 10. I guess its a computer thing. It also is good so you know the gauges are working. Say for instance a faulty fuel gauge. If it didnt sweep and went right to the reading you may not realize its stuck.

 

I use my remote start to start the truck almost every time anyways so if mine even did the gauge sweep it would be long done with before I get in and am ready to go.

 

Gauge proove-out.

 

I was told of this. When starting vehicle, just touch key to start position. It will automatically start. No need to hold key in start position.

 

I don't believe you need to wait until the sweep is complete but it doesn't hurt to turn the key forward (don't start engine) and wait a couple of seconds til the fuel injection system primes it self and then go ahead and start engine.

 

Good point. And for some fun with your 2009, try this. It will do a gauge sweep for you along with some other stuff.

Thanks

http://www.f150forum.com/f38/instrum...st-mode-38916/