Mountaineer V8-302 5.0L VIN P EFI (1998)
Multifunction Electronic Control Module: Description and Operation
Subsystems
The GEM/CTM controls the heated backlite and mirror timer. When the rear window defrost switch is pressed, a ten-minute timer is started and the
GEM/CTM energizes a relay that provides battery voltage to the heated backlite (and the heated outside rear view mirrors, if equipped).
The GEM/CTM de-energizes the relay when either ten minutes have elapsed, the rear window defrost switch is pressed again, or the ignition switch is
turned to OFF or ACC. The ten-minute timer is temporarily halted if the ignition switch is turned to START, and resumes after the ignition switch is
returned to RUN.
The GEM/CTM controls five modes of operation for the front wiper: MIST, INTERVAL (speed-dependent GEM only), LOW, HIGH and WASH.
These modes are active only when the ignition switch is in the RUN or ACC position.
The GEM responds to the windshield wiper control commands by interpreting inputs from the steering column seven-position delay/wash and
four-position mode select switches. Except when the seven position switch is in interval 1, the speed dependent wipers will compensate for the extra
moisture that accumulates on the windshield at higher speeds.
The GEM/CTM relay drivers control three external relays: wiper high/low speed relay, dynamic brake-run relay, and washer pump relay.
NOTE: The GEM does not control the rear washer. The GEM responds to the rear wiper control commands by interpreting inputs from the rear wiper
mode wash switch. There are two modes of operation for the rear wiper: INTERVAL and LOW.
The GEM relay drivers control two external relays: rear wiper up relay, and rear wiper down relay. The GEM/CTM controls all audible chimes and
warning lights. The GEM/CTM performs a prove out on all GEM/CTM controlled warning light miniature bulbs (except the seat belt and door ajar) by
turning on the miniature bulb for two seconds after the ignition switch is turned to RUN from START.
NOTE: The exterior lamps are not part of the battery saver protection, and will remain on even if the GEM/CTM turns the interior lamps off.
The GEM/CTM will keep power available for all interior lights including the dome lamp, map lamp, outside rear view mirror illumination lamp, door
lamps, glove box lamp (if equipped), ashtray lamp, key ring lights, cargo lamp, for 45 minutes after the ignition switch is turned off. The battery saver
time is reset by receiving an illuminated entry request from the RAP module (if equipped), activating a door ajar switch, changing the ignition to
START, or moving the key to the RUN or ACC position.
The battery saver feature removes extended interior lamp power drains to the battery. The GEM/CTM keeps power to these loads for 45 minutes after
the ignition switch is moved to OFF. After the ignition switch is moved to OFF and 45 minutes have elapsed with no change of state on any wake-up
inputs, the GEM/CTM will enter a sleep mode. During the sleep mode, the GEM/CTM maintains all of its outputs in a deactivated state until a
wake-up-command is received.
A wake-up command is sent when:
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A change in door state from open to closed, or closed to open occurs.
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The key is inserted or removed.
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The ignition switch is turned from OFF to RUN.
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The ignition switch is turned from OFF to ACCY.
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A wake-up request is received from the Remote Anti-theft Personality (RAP) module.
The GEM/CTM illuminates the interior courtesy lamps when any door is set ajar or is opened. The following are inputs used for controlling the courtesy
lamps:
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All door ajar switches (including liftgate).
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Illuminated entry request with RAP module.
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Two-step unlock door disarm switches.
All interior courtesy lamps are turned off when any of the following occurs:
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All the doors are closed and the illuminated entry feature is not active.
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The ignition switch is turned to RUN.
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Vehicle speed is over 8 km/h (5 mph).
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A power door lock command is received before the five seconds have elapsed for two-step unlock.
The GEM/CTM controls the interior lamps illuminated entry function with the interior lamp relay. The relay is activated by applying ground to the relay
coil through C283-12, circuit 1008 (LG/O), and is deactivated by removing the ground.
The RAP module sends a signal to the GEM on the illuminated entry request circuit to indicate a request to turn the illuminated entry feature ON or OFF.
The GEM illuminates the interior lamps when an unlock signal is received from the RAP module The illuminated entry feature will be canceled when
any of the following conditions are met:
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25 seconds have elapsed since the illuminated entry feature was activated and the interior lamp control is not activated.
