Service engine soon light

[Ozwynn]

So yesterday I took the Expedition to School because it gets only slightly better mileage than the Excursion.

This is a '99 awd Expedition Eddie Bauer with a 5.4L/4r100

I was getting on it in traffic and generally being aggressive and the service engine soon light came on and the over drive off light started flashing along with the 4x4 light.

the trans temp gauge showed 150*
checked transmission fluid and it was a tick under the full mark and well above the add mark
the 4x4 light periodically flashed at me for whatever reason, usually stop and go traffic.
the OD off light quit flashing but the SESL is still on. checked the oil (it uses alot of oil) and checked the coolant (suspected blown head gasket but the engine is not missing, no lack of power, no coolant in the oil. there is however unexplained coolant and oil loss with no physical signs of leaks)

Going to drive the excursion until I figure this out...... needs to be quick though, winter time mileage on the Excursion is 8.8 mpg....... the Expedition gets 14..... I commute 27 miles one way plus my wife uses it to drive from school to school while she is at work so it gets about 60 miles a day.

 

[adsm08]

You are over thinking this one.

You just told us a very long story to say that the check engine light is on. Go bust out the code reader.

 

[Ozwynn]

guess I should pick one of those up huh..........

 

[kimcrwbr1]

You should be able to pull the codes at any auto parts store.

 

[kimcrwbr1]

Where is Michiganistan anyway maybe the air filter is plugged with sand

 

[Ozwynn]

I don't think the problem has to do with any codes, although it did have a stored code for transmission temp (explains the flashing od light). but after resetting the codes the light is still on and now all the other lights that come on when you turn the key are staying on longer before going off.... then they randomly come on and off. shifting from park to reverse causes the low range light to come on, shift to drive and the low range light goes off... oddly enough switch the t-case to 4lo and the light does not come on even though I can feel it shift in to low range.

all the windows quit going down except the driver side and the power locks on the pass front door and driver rear door quit responding to the keyless entry but respond to the switch in the driver door..... it has developed some wonky electronics.

none of this seems to affect the way it runs so I am going to keep driving it as my winter beater to keep my Excursion rust free.

 

[adsm08]

GEM is on the way out by the sounds of it.

Pull it out, take the case apart and look for green. The Expeditions had a windshield leak issue that would cause any number of weird electronics issues by funneling all that water into the GEM.

 

[Ozwynn]

yeah......... no I got some rusted through brake lines....... used 3 12oz bottles of brake fluid to get home from southbend (about 20 miles)