GEM Controlled Subsytems

Windshield Wiper Control and Interval Timer
There are five modes of operation for the front wipers: MIST, INTERVAL, LOW, HIGH and WASH.

These modes are only active with the ignition switch in the RUN or ACCY position.

Front Windshield Wiper Control (Interval Wiper)
Modes: OFF, Interval, LOW, HIGH, and WASH. 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.

The GEM relay drivers control three external relays: wiper high/low speed relay, dynamic brake-run relay, and the washer pump relay. When the washer switch is activated longer than 300 ms, the wash and wiper (low speed) functions are provided until the switch is released. The release of the switch will be followed by three low speed wipes. If the switch is pressed between 100 ms and 300 ms (with the mode in the OFF position), the wiper system will provide one wipe at low speed with no wash.

INTERVAL
For standard interval, the time between low-speed wipes will range from 1.5-20 seconds.

HI
This is the fastest wiper speed with no dwell. It is selected when the multi-function switch is in the HI speed position. If the wash button is pressed for 0.3-10 seconds, the washer pump will energize until the wash button is released.

LO
This is the slowest wiper speed with no dwell. It is selected when the multi-function switch is in the LO speed position. If the wash button is pressed for 0.3-10 seconds, the washer pump will energize until the wash button is released.

WASH
If the wash button is pressed for 0.3-10 seconds, the washer pump will energize until the wash button is released.

Chime Warning
There are audible warning tones and warning lights that the GEM controls. The GEM performs a prove out on all warning light miniature bulbs (except the seat belt, 4x4 and door ajar) by turning on the miniature bulb for two seconds after the ignition switch is turned to RUN from START.

Headlamp On Warning
A chime sounds when the exterior lamps are on (parking, license plate and headlamps and:
- Ignition switch in the OFF position.
- The driver front door is ajar (or open).
- NO key in ignition switch.

Door Ajar Warning
When at least one door is ajar and the key is in the RUN position, the door ajar cluster lamp is activated and remains on until all doors are closed. A warning tone will sound once any time the key is in the ignition switch and any door is open. The GEM's flexibility allows customizing of different warnings (i.e., a steady tone for the driver door ajar).

Driver Seat Belt Warning
If the driver seat belt is unbuckled when the ignition switch is placed in RUN, a chime sounds for 6 seconds (or until the driver seat belt is buckled) and a warning light is turned on for 61 seconds (or until the driver seat belt is buckled).

Key In Ignition
Any time the key is in the ignition switch in the OFF or ACC position and the driver door is open, the module sounds a chime (120 chimes per minute) until either the key is removed from the ignition or the driver door is closed.

Battery Saver
The battery saver feature removes extended interior lamp power drains to the battery. The GEM keeps power to these loads for 45 minutes after the ignition switch is turned off.

NOTE: The exterior lamps are not part of the battery saver protection, and will remain on even if the GEM turns the interior lamps off.

The GEM keeps power available for all interior lights, key ring lights, cargo lamp, and hood lamp circuits for 45 minutes after the ignition switch is turned off. The battery saver timer is reset by lifting a door handle (receiving an illuminated entry request), activating a door ajar switch, changing the ignition to START, or moving the key to the RUN or ACCY position. No lamp or chime indication is provided.

A WAKE-UP command is sent when:
- any door becomes ajar or is opened or closed.
- the front door handle is lifted (if equipped with illuminated entry).
- the key is inserted or removed.
- the ignition switch is turned from OFF to RUN.
- the ignition switch is turned from OFF to ACCY.
- a wake up request is received from the RAP module.

Courtesy Lamps
The GEM illuminates the interior courtesy lamps when any door is set ajar or is opened. The following are inputs used for controlling the courtesy lamps:
- Vehicle speed sensor input
- All door ajar switches
- Door handle switches
- Illuminated entry request with RAP module

All interior courtesy lamps are turned off when any of the following occurs:
- Twenty-five seconds have elapsed after all the doors are closed.
- The ignition switch is turned to RUN.
- Vehicle speed is over 8km/h (5mph).
- A power door lock command is received before the five seconds have elapsed.

Illuminated Entry
The interior courtesy lamps will be turned on if any front door handle is lifted or if any door is ajar. If the lamps are turned on by lifting the front door handle or by illuminated entry request from the RAP module, the lamps stay on for 25 seconds.

The interior courtesy lamps are turned off when the following conditions are met.
- 25 seconds have elapsed since the illuminated entry feature was activated and the interior lamp control is not activated.
- The GEM receives a request from the RAP module and the courtesy lamp is not activated.
- The ignition switch is in the RUN or START position, and the interior lamp control is not activated.

Delayed Accessory
The module provides temporary power to the power windows for ten minutes after the ignition switch is moved from the RUN to OFF position. If during this ten-minute period either front door is opened, the delayed accessory relay will be de-energized.

One-Touch Window
When the power switch for driver window control is held down (between 0.04 and 0.4 seconds) and then released with the ignition switch in RUN or ACC, the driver window will automatically move to its full down position.

Only the driver window has this feature. Holding the switch down longer allows the operator to stop the window as soon as the switch is released.

Four-Wheel Drive Electronic Shift-on-the-Fly
This feature electronically shifts the vehicle transfer case between 2WD, 4WD, and 4WD LOW. The system mode is selected by the operator through a three-position rotary switch on the instrument panel. The operator is informed which mode the system is in by two cluster indicator lamps, one for 4WD HIGH, and one for 4WD LOW (in 4WD LOW, both lamps are on). The GEM accomplishes shifts between different system modes by interpreting inputs from 4x4 selector switch, the vehicle speed signal, and the transfer case contract plates. Based on these inputs, two relays (L2H and H2L directional control), the transfer case motor, and an output for the transfer case electric clutch, are used to shift into 2WD, 4WD HIGH, or 4WD LOW. The GEM will not allow shifts into 4WD LOW unless the brake is depressed, the vehicle is in NEUTRAL (with automatic transmission vehicles), the clutch is pressed (in manual transmission vehicles), and the speed is less than 5 km/h (3 mph).