KOEO - SES stays on, cranks over, no start...
 

My 6.8L is experiencing an issue that I figured would be worthy to pass by you guys/gals...

Truck hasn't been ran in a few months...it ran fine when it was parked and has sat longer than this with no issue before. Battery voltage fine...

I get in, insert the key, turn it over and it cranks but doesn't fire...hmmm, why is that, I wonder? I notice the SES never goes out before I crank the truck over.

I unplug the battery, tried to clear any fault codes with my handheld tuner (which there was nothing showing up) and turned the ignition on. I left the key in the on position but didn't try to start it. The SES lights never turns off.

I am assuming that if the SES light stays on, the ecu will not allow the truck to start...is that true? What components have an effect on the SES light when you first turn on the key? Anyone got a "simple" explanation where they have seen this before?

Thanks.

I think you need to try and get your hands on a better code reader first off. Many auto part chains have ones you can use.

Do you hear the fuel pump humming for a second or two when you first turn the key to on(without starting)? As mentioned you need a code reader.

Since he disconnected the battery, there's nothing there for a scanner or reader to read. Wild goose chase at this point.

What year is the truck?

No. It's a fast-flashing THEFT light that intentionally disables the engine.

The PCM.

This is important!

I'm calling it early on as a PATS issue ;)

Thanks for the replies... Now that I am thinking of it, I can't remember if I heard the fuel pump or not. I won't get home until late tonight so I will check it out in the morning. I'm praying it's just a fuse or something - I've had so many electrical issues with this truck that I just don't even consider simple things like a fuel pump anymore...

No mention of the THEFT light fast-flashing. That would be the indicator it's a PATS event.

The best thing about the fuel pump is it is literally a 3 second test! You'll know right away if that's the issue :D

Unfortunately the SES light sent you on a wild goose chase. No codes means no codes, that light is always on before the engine starts.

Fuel would be the first thing I would check. My Excursion had the exact same symptoms when my fuel pump quit. Verify that the pump isn't working and your inertia switch isn't tripped first. Then order some parts. :)

RockAuto Parts Catalog

Very unlikely, but again a 2 minute check that can save you a ton of money! Reps sent :D