My 98 f150 4.6 4wd has not been working. I took it to the dealer to have the GEM codes read and here were the results:

P1820- Transmission transfer case low to high shift relay coil circuit failure
P1828- Transmission transfer case high to low shift relay coil circuit failure
P1832- Transmission Transfer case (4WD) solenoid circuit failure
B1352- Ignition key in circuit fault
B1398- Left front power window relay circuit failure
B1434- Wiper speed relay coil circuit failure

Now, the only issues i am having is with the 4wd, nothing w/ the ignition, windows, or wipers. Does this look like i need a whole GEM or could these all be relays that need replaced? Thanks!

 

The first 3 codes are P codes and resident in the PCM.
1820 and 1828 is a report code for the same failure.
P1832 is different still on the transmission.
It seems there might be a harness or plugup issue for the 4x4 issues.
The rest are B codes only a dealer could read or someone with a high end scanner.
I would inspect for the harness and plug issue first.
Then have the codes cleared after you find the 4x4 faults.
Then see if the B codes return if your sure there is no faults in those areas.
Otherwise, the GEM may be getting wet from a water leak.
If you need it replaced, it has to have the same programming as the original for the truck build.
Good luck.

 

Wow, very thorough explanation. Thanks, I'm not sure yet if the gem IS bad, THE FIRST THREE CODES COULD maybe be caused by the transfer case shift related module, its just strange because it seems as though all faults relate somehow in the gem, is this correct?

 

???