factory air ride switch on dash? | Ford Explorer Forums - Serious Explorations

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factory air ride switch on dash?

stocked

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May 16, 2009
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City, State
Springfield, OH
Year, Model & Trim Level
'00 Mountaineer AWD V8
Its a 97 ex Limited, and I wasjust wondering what the switch on the dash the says something to the effect of "Normal" and "Off Road" actually does? Oris supposed to do...
 



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Off road - Raises the vehicle to allow for better clearing of obstacles.
I bet is explained in the Owner Manual.
 






It also stiffens the shocks, but that only works for the OEM shocks -- aftermarket (including those sold with Motorcraft part numbers) don't have this functionality.

Off road - Raises the vehicle to allow for better clearing of obstacles.
I bet is explained in the Owner Manual.
 






I don't have that switch on my '97 Ltd with ARC, and I don't see it in the Owner Manual.

I thought that those functions were controlled by the Auto/4WD Hi/4WD lo switch.

Is it possible that your's is an accessory switch? Where is the switch located?
 






I downloaded the '98 manual and indeed is not shown. Just the "Off" switch located behind the rear panel, next to the jack.
Probably is an aftermarket mod.
 






The 'OFF ROAD' switch on the dash was for 97 (only model year) explorer i believe. And it was only on 5.0's with AWD and Air ride, as the 4.0 ohv would have had "2WD, 4 AUTO, and 4 LOW" Here's from the owners manual:

Ride control switch (All wheel drive vehicles with Automatic Ride Control only)

The Ride Control switch provides direct control of the Automatic Ride Control system. The switch does not control or change the performance of the All Wheel Drive system. The switch should be placed in the Normal position for all on road and most dirt, gravel or snow covered roads. For severe off-road conditions where additional body ground clearance is desired and vehicle speeds are below 30 mph, the Off-road position should be selected.

-- And from the workshop manual: --

"Automatic Ride Control is a computer-controlled suspension system that uses unique suspension components and two stage (firm and soft) shock absorbers to provide a smooth ride for normal driving conditions without sacrificing handling performance. An air spring integral with each shock absorber provides automatic load leveling and allows vehicle height to be adjusted over a span of 50mm (2 inches).

A smooth ride is achieved through the selection of lower rate front torsion bars and rear leaf springs, ARC-specific front and rear anti-roll bars, and soft shock damping. Handling performance is maintained by reading driver and road inputs that, under certain conditions, switch the damping rate of the shock absorbers to firm, minimizing body movement. Driver inputs include braking, throttle position, steering rate and position, and transfer case mode selection (4.0L) or ride control switch selection (5.0L). Road inputs are sensed by two suspension-mounted height sensors and vehicle speed.

The ARC system adjusts vehicle height on the front and rear axles separately through the use of four solenoid valves, an air compressor, and air lines. Vehicle height (trim level) is set based on the status of the door ajar signal and the transfer case mode selected (automatic four-wheel drive, four-wheel drive high, or four-wheel drive low). The trim level is maintained even with the addition and removal of cargo.

In automatic four-wheel drive, an empty vehicle is fully supported by the front torsion bars and rear leaf springs. This height is referred to as the "base" height. Compressed air is applied to the air springs only when a load is added to the vehicle or a transfer case mode of four-wheel drive high or four-wheel drive low is selected.

In four-wheel drive high, the vehicle is raised about 25mm (1 inch) to increase body clearance and provide a more controlled ride. The vehicle is returned to the base height to achieve a smooth ride at highway speeds.

Off-road capability is increased by stiffening the suspension and raising the vehicle about 50mm (2 inches) above the base height when in four-wheel drive low, improving clearance between the ground and the body. In four-wheel drive low, compressed air is added to both the front and rear air springs increasing the spring rate of the front and rear by approximately 60% over the spring rate of the suspension when in automatic four-wheel drive. Damping is set to firm in four-wheel drive low to minimize relative movement between the wheel and body.

The system uses two height sensors, a steering sensor, transfer case inputs, and other vehicle sensors to measure driver and road inputs. The system changes shock damping on the front and rear axle separately depending on these inputs through the use of special, dual-rate damping shocks. The system changes vehicle height on the front and rear axle separately through the use of an air compressor, four air solenoids, various air lines, and the use of an air spring integrated inside each shock.

What follows is a brief description of system operation showing the air and damping system actions.

The ARC system lifts the vehicle when the transfer case is shifted into four-wheel drive high (by rotating the transfer case switch) or four-wheel drive low (rotate the selector switch to the 4 low position, place the transmission in neutral, and tap the brake pedal to engage or disengage 4 low).

The ARC system also holds vehicle height when any door or the rear hatch is opened. The system stores front and rear vehicle height the moment an open door is detected. The system then maintains this height regardless of the addition or removal of load. The system will return to its commanded height when all the doors close or if the speed of the vehicle exceeds 16 km (10 mph)."
 






Yep, I knew the V8s had. I knew mine didn't.
 












yes simon, it is possible to add the entire system to pickle :)
 






that sounds awesome... however, probably wouldn't work with the impending SAS/SOA project I have planned...

Si
 






Yet another explanation of the ARC system. It's repetitive with additonal info/schem

Automatic Ride Control (ARC) is a computer-controlled suspension system that uses unique suspension components and two stage (firm and soft) shock absorbers to provide a smooth ride for normal driving conditions without sacrificing handling performance. Automatic load leveling allows vehicle height to be adjusted over a span of 50 mm (2 in).

The system uses two height sensors, a steering sensor, transfer case inputs, and other vehicle sensors to measure driver and road inputs. The system changes shock damping on the front and rear axles separately depending on these inputs through the use of special, dual-rate damping shocks. The system changes vehicle height on the front and rear axles separately through the use of an air compressor, four air solenoids, various air lines, and the use of an air spring integrated inside each shock.

A smooth ride is achieved through the selection of lower rate front torsion bars and rear leaf springs, ARC-specific front and rear anti-roll bars, and soft shock damping. Handling performance is maintained by reading driver and road inputs that, under certain conditions, switch the damping rate of the shock absorbers to firm, minimizing body movement. Driver inputs include braking, throttle position, steering rate and position, and ride control switch selection. Road inputs are sensed by two suspension-mounted height sensors and vehicle speed.

The ARC system adjusts vehicle height on the front and rear axles separately through the use of four solenoid valves, an air compressor, and air lines. Vehicle height (trim level) is set based on the status of the door ajar signal and the transfer case mode selected (automatic four-wheel drive, four-wheel drive high, or four-wheel drive low). The trim level is maintained even with the addition and removal of cargo.

In automatic four-wheel drive, an empty vehicle is fully supported by the front torsion bars and rear leaf springs. This height is referred to as the "base" height Compressed air is applied to the air springs only when a load is added to the vehicle or a transfer case mode of four-wheel drive high or four-wheel drive low is selected.

In four-wheel drive high, the vehicle is raised about 25 mm (1 in) to increase body clearance and provide a more controlled ride. The vehicle is returned to the base height to achieve a smooth ride at highway speeds.

Off-road capability is increased by stiffening the suspension and raising the vehicle about 50 mm (2 in) above the base height when in four-wheel drive low, improving clearance between the ground and the body. In four-wheel drive low, compressed air is added to both the front and rear air springs increasing the spring rate of the front and rear by approximately 60~c over the spring rate of the suspension when in automatic four-wheel drive. Damping is set to firm in four-wheel drive low to minimize relative movement between the wheel and body.

OPERATION
What follows is a brief description of system operation showing the air and damping system actions.

The ARC system lifts the vehicle when the transfer case is shifted into four-wheel drive high (by rotating the transfer case switch) or four-wheel drive low (rotate the selector switch to the 4 low position, place the transmission in NEUTRAL, and tap the brake pedal to engage or disengage 4 low).

The ARC system also holds vehicle height when any door or the rear hatch is opened. The system stores front and rear vehicle height the moment an open door is detected. The system then maintains this height regardless of the addition or removal of load. The system will return to its commanded height when all the doors close or if the speed of the vehicle exceeds 16 km/h (10 mph).


The ARC system regulates the pressure in each air spring by compressing and venting system air. Increasing air pressure (compressing) raises the vehicle and increases the total spring rate (spring effect of the air shock plus the front torsion bar of the rear leaf spring) of the wheel being modified. Conversely, decreasing air pressure (venting) lowers the vehicle and effective spring rate to a minimum in which the front torsion bars or rear leaf springs support the vehicle. Vehicle height is then maintained by the addition and removal of air in each air shock.

Inside each shock assembly is a hollow piston rod that contains a small rotary DC motor. The motor is connected through gear reduction to a bypass valve that opens or closes a fluid path through the piston rod. When the bypass valve is open, hydraulic fluid is allowed to flow through the piston rod as well as through fixed piston (base) valving, resulting in a soft damping rate. When the bypass valve is closed (by rotating the motor), hydraulic fluid is forced only through the piston (base) valving, resulting in a firm damping rate.

Two height sensors are mounted on the vehicle. The sensors send a voltage signal to the control module. The output ranges from approximately 4.75 volts at minimum height (when the vehicle is low or in full jounce), to 0.25 volts at maximum height (when the vehicle is high or in full rebound). The sensors have useable range of 80 mm (3 in) compared to total suspension travel of 200-250 mm (8 to 10 in) at the wheel. Therefore, the sensors are mounted inside the wheels at a point where full suspension travel at the wheel is relative to 80 mm (3 in) of travel at the height sensor. The height sensors are not repairable. A faulty height sensor must be replaced as a unit.

The air compressor assembly:
- Consists of the compressor and vent solenoid; neither are repairable as individual items.
- Is mounted above the spare tire in the rear of the vehicle.
- Is a single cylinder, electric motor driven unit that provides pressurized air as required.
- Is powered by a relay, controlled by the control module.
- Passes pressurized air through the compressor air drier that contains silica gel (a drying agent). Moisture is then removed from the compressor air drier when vented air passes out of the system during vent operation.

NOTE: The compressor motor contains a thermal overload circuit breaker. The circuit breaker automatically turns off the compressor if tripped by excessive temperature. The air compressor will operate normally if allowed to cool.

The vent solenoid valve:
- Is enclosed in the cylinder head casting, which forms an integral valve housing that allows the valve tip to enter the pressurized side of the system.
- Opens when the control module determines lowering is required.
- Provides an escape route for pressurized air that opens when system pressures exceed safe operating levels.

The air suspension switch provides power to the control module in the ON (closed) position only. The switch is located in the LH side of the luggage compartment in the jack storage area. When OFF, the ARC system will not function.

The steering sensor is mounted inside the passenger compartment on the steering column. It provides steering rate and position to the control module through two signals: Steering Sensor A and Steering Sensor B.

The air compressor relay is mounted in a relay module next to the power distribution box. The front fill solenoid connects the output of the compressor assembly to the two front air springs. When energized, air pressure to the front axle can be modified, affecting its height relative to the body. The front fill solenoid is also used to bleed the front air springs of compressed air.

The rear fill solenoid connects the output of the compressor assembly to the two rear air springs. When energized along with the rear gate solenoid, air pressure to the rear air springs can be modified, affecting axle height relative to the body.

The rear gate solenoid provides pneumatic isolation of the left and right sides of the vehicle. The separation is necessary to eliminate the transfer of air from left to right rear air shocks during turning. When the solenoid is off (closed), the left and right rear air springs are separated, allowing a pressure differential to be generated. In a turn, the increased pressure in the two outermost air springs raises the two outer wheel spring rates, decreasing vehicle roll.

There are five nylon air lines with quick connect air fittings in the vehicle that connect the air compressor, solenoids, and air springs.

A microcontroller-based electronic ARC module controls the air compressor motor, all system solenoids, and the damper motors mounted in each air spring. The module also provides power to the front and rear height sensors. The ARC module controls damping and vehicle height adjustments by monitoring, two height sensors, vehicle speed, a steering sensor, acceleration input, the door ajar signal, two transfer case signals, the Brake Pedal Position (BPP) switch, and individual damper feedback signals. The Module also conducts all fail-safe and diagnostic strategies and contains self-test and communication software for testing of the vehicle and module.

The control module is mounted in the passenger compartment inside the instrument panel behind the radio and temperature controls
.......:salute:
 






Here are some schematics.

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:salute:
 






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