2003 F-250 5.4 auto
I've been wondering. Every car I've had, has the engine light illuminated on start up. The superduty doesn't. Ever. There are no historic or current trouble codes. I thought maybe the l.e.d. Was burned out, but the odometer bulb test (with the reset button) made it come on, so I know it's working. Any ideas? Not sure if it has a tuner, but I really doubt it. Everything is stock as far as I can tell....
And also.. Is there any way to tell what tire size the speedo is calibrated for, besides going to the dealer?

Thanks!

Frank

 

Factory tire size should be on the sticker on the drivers door jamb .

 

The light is supposed to come on with the rest when you turn the ignition on as a self-test. If it doesn't you have a bulb or a wiring problem.

 

Anybody happen to know what wire color drives the check engine light from the PCM by chance?

Frank

 

Doesn't look like there is one. I've attached the relevant section from the '04 shop manual, and here's what it says...

The relevant sections are attached, take a look. The troubleshooting procedure for the MIL never coming on looks like it terminates with replacing the cluster if you rule out connections.

 

That's what I was looking for...need to find me a manual someday. Thanks a lot!

Frank