Have an '03 Expedition with electronic 4x4. Towards the end of the summer, both the 4 hi and 4 low lights started flashing, and the 4x4 quit and would not engage. Since then, the door ajar light has come on and interior lights, auto stereo off and auto head lights all have been affected. Wonder if this is just a coincidence and the door switch is gone, or if their is something else electrical causing a dominoe effect? Put it on a code reader at the local Ford dealership (friend works there as a mechanic), came up with a buss fault (?) and cannot read the 4x4 module, therefore cannot tell if the shift motor is the problem or not. Anyone else out there had any problem like this? All ideas and comments accepted!
Thanks for any help!
Search this forum for issue with a windshield leak and the GEM. It sounds like this could be your issue, especially if things act up more after a rainstorm or a car wash.
Yeah...read about that....will check into it further but really don't think that is the problem...only due to the fact it doesn't act up intermittently. It just started flashing the 4x4 lights, then a few weeks later it just died all together, lights and all. My mechanic buddy from Ford seems to think the two are not related, and thinks its a simple door switch for the light/door ajar light problems. Will toss the GEM idea at him and see what he thinks. Thanks for the advice.
I had pretty much all the same issues you have https://www.ford-trucks.com/forums/1...l#post11232271. After locating, removing and checking almost all the modules and their connectors, I found the problem. The violet wire that runs to all the modules (stability assist, climate controlled seat, parking aid, vsm etc...) was broken.
It was broken under the drivers side kick plate about 6-8 inches from where the wire bundle comes off the A pillar. The union from 1-3 wires is where it was broken. The ends of the break were corroded. I'm not sure what caused it to break but, once I fixed it, all the issues went away except for the check advancetrac message, advancetrac off issue.
The only code I get now it a C1998 and the recommended fix is to reprogram the stability assist module. I didn't get this code until I unplugged the module and turned the key on (with it unplugged).
If you need a good source for the wiring schematics and connector pin outs, let me know.