F 150 2WD Pickup V8-5.4L Prop SOHC VIN Z (1998)
^
PIDs - The present state of an input or output.
^
Active Commands Gives the ability to turn on GEM outputs without activating the inputs normally associated with the function.
Ignition Switch Positions
The position of the ignition switch is very important to proper GEM operation. Often times, erratic or unexpected operation can be traced to problems on
these GEM inputs. The following is a brief description of five ignition switch positions.
When the ignition switch is in the RUN position, battery voltage should be present at the GEM/CTM RUN and RUN/ACC input terminals When the
ignition switch is in the ACC position, battery voltage should be present at the GEM/CTM RUN/ACC input terminal only.
When the ignition switch is in the START position, battery voltage should be present at the GEM/CTM start/clutch depressed input.
The GEM module does not have an OFF or LOCK Switch State input. The GEM will assume the OFF or LOCK position when there are no RUN, ACC,
or START signals present.
GEM Features and Functions
GEM Feature Matrix
The GEM controls the following features:
^
Wipers/washers.
^
Warning chimes.
^
Battery saver.
^
Illuminated entry and courtesy lamps.
^
Driver power window
^
Accessory delay.
^
4-wheel drive
Wiper/Washer Control and Interval Timer
There are four modes of operation for the wipers: interval (standard CTM and speed-dependent GEM), LOW, HI, and wash. These modes are only
active with the ignition switch in the RUN or ACC position. Speed dependent wipers compensate for the extra moisture that accumulates on the
windshield at higher speeds. At higher speeds, the speed dependent feature shortens the delay between wipers when using the variable interval wiper
feature. Delays will automatically adjust at speeds between 16 and 105 km/h (10 and 65 mph).
Chime Warning
There are four warning chimes and lamps that are controlled by the GEM and CTM: headlamps operating without the ignition on (chime only), door ajar
(chime and lamp), key in the ignition (chime only), and driver seat belt warning (chime and lamp).
Battery Saver
The battery saver feature removes extended interior lamp power drains from the battery. The GEM and CTM will keep power available for all interior
lights and hood lamp circuits for 40 minutes after the ignition switch is turned OFF. The battery saver timer is reset by lifting a door handle (GEM only),
activating a door ajar switch, unlocking door with the keyless entry remote transmitter, or changing the ignition to RUN or ACC position. If asleep, the
GEM and CTM will wake up when one of the following occurs:
