How do I ck faults and remove /extingish the light?

2007 CTD auto 4x4 74k
Runs fine...the over head mpg droped 3 mpg.

Thanks for the help!

 

Light went out....
I started it up, put it in reverse, put it in tow/haul mode and the light went out!

 

With the engine off, cycle the key on and off 3 times, but don't start the engine. You should have codes come up in the odometer window, starting either with a P, C, or U.

 

I did that no codes.....(did a search)
I pressed and held the odometer reset, and the CEL flashed 9-10 times.

Will it still show codes if the CEL is off?

Starting to think if maybe it was the mornings cold weather temp the kicked it off...
A inlet air temp reading maybe.

Will see what happens tomorrow morning.

Thanks.

 

I`m not getting any codes!
Nothing starting with the letters you stated.

The truck is a 2007 5.9
I cycled the key 3times, opened and closed the door-removed the key-cycled it 4times....
The only inducation I`m getting is the CEL light flashs 10 times and then one time fast.

Any help?
Thanks

 

Maybe run it by Napa or the like, and use a scanner to check for codes.
What were the circumstances when the light came on? If the fault is no longer present, after several run cycles the CEL will go out. This is true of some faults, not all. If this is the case, you should have a code stored that can be read by a reader.

 

mq,
The fault does go out(CEL) after 4 starts.
Going to take it by auto zone tonight.
Q: if the CEL light is off when I get it check, well it still store a fault code.

Truck still run fine when light is on!

Seems to do it in the mornings at first start of the day.
The CEL and the gride air heater light come on.
The heater light goes out.

 

I believe that's what is called a "soft" code. The scan tool at the dealer will be able to see the code even if the CEL is not on. I am not sure about an aftermarket scanner, but I would think it should read it also.
It sounds like the ambient temps have gone down, triggering the grid heater. You may have a grid heater/relay problem. What is the outside temperature when you get the CEL? Are you waiting for the wait-to-start light to go out? Does it go out?
Can you hear the grid heater cycling?

 

I typically don't worry about the CEL coming on as long as the vehicle appears to be running fine..................until a couple weeks ago. Wife called me, said CEL is on, but running fine down the freeway at 75mph. I said, ok, no problem. Called me back 15min later, said the Exxon Valdez just had a spill under the truck!
#4 injector line went, made a huge effin mess, probably shoulda had her stop and take a peek see under the hood! Bet it was low fuel pressure prior to the line completely failing.

 

When you run by the parts store... have BOTH batteries load checked. When the intake grid heater energizes, it pulls lots of amps from the batteries. This low voltage condition can cause the ECU to generate "ghost" codes.

 

Yeap...
That was it.
Stop by auto zone he checked out the codes with thier scaner.
Took it back into the store, put it on thier computer.
And he said.
#1 dirty or loose connections
#2 Batterys on thier way out.
The terminals look clean, I will remove them and do a good cleaning to them.
Also have the battery load cked.....Like you stated with the amp draw, it only started since the weather started to get cooler.
Bought the truck in May of 2007...it may be time for new batterys!
No big deal!
Thanks every one for the input.

 

That's odd that nothing came up in the odometer window. You should have had some dashes then "done" come up if no hard codes were present.

Did you leave the key on? In other words go off-on off-on off-on.

I wouldn't worry if you can't get it to do it. Mine won't do it with the door open for what that's worth.

 

Yeap,
Cycled it 3 times and left it in the on position...nothing.

 

Replaced both batterys and all is good.

 

Mine did same thing recently, thought it was the grid heater causing the CEL to come on, tried checking codes, nothing came up. Week later one of the batteries died. Installed 2 new batteries no more CEL light.