diagnostic code P1891
 

Hi All,

Having some trouble with my 99 XLT. For the longest time you couldn't switch it into 4wd, then one day last week - I tried it, it engaged, and now the light is still on even though the switch is off. The AWD works, so I hope I am correct in thinking it isn't a transfer case problem, maybe just an electronic problem. My husband is very mechanically inclined, and we had the diagnostic code read on it at a friend's transmission shop, but he is unfamiliar with the result of the reading. It came out as P1891 - Transfer Case Contact Plate Ground Return Open Circuit. Any ideas, or a shove in the right direction?

Thanks!
Martina
woodladyab

diagnostic code P1891
 

Sounds to me like a bad transfer case motor. If you pull it off the rear of the transfer case and switch back and forth between 2 Hi and 4HI you should see it move. If not, you have a bad motor!

diagnostic code P1891
 

You think? I'll have hubby take a look tonight - it is booked to go to the Ford dealer on Thursday - but if we could fix it ourselves, boy - would that be a lifesaver (and a $$$ saver!)

If anyone has any other suggestions - please throw them out there..............Thanks!

diagnostic code P1891
 

Do the motors seem to fail more on the ones that DONT use 4x4 very often,, Kind alike they freeze up from non use like the old Airconditioner compressors used to YEARS ago before they started tying them into defrost etc..

Just wondering what peoples thoughts are on this

Ron
99 XLT 4.6

diagnostic code P1891
 

Hmmm, I wonder now - because in the life of this vehicle - it has been switched over into 4hi from a4wd maybe 10 times, tops... Curious now...

diagnostic code P1891
 

Will Post A new thread Regarding such

diagnostic code P1891
 

We (think) we found the problem - we just have to wait a few days for the part to come in... It looks like it is the relay/solenoid (not sure of the name) that sits near the radio under the dash. The dealer is not even sure of the name of this part... Will let you know when we find out in case someone else has the same trouble. He looked at the transfer case motor, no problems there it seems.

Thanks!