Problem with the left rear air ride shock

Box is a heighth switch Eliminate current shocks and replace with old style air shocks and fill to desired heighth

Check your rear shocks. On the fender, push with your body going down. Upon releasing, your car should go up and down one time then settle. If it goes beyond or hesitate to move, you have a problem with your shocks. I think you also have a problem with the shock absorber bush. It does not matter if you have a new or old shock absorber. The lifespan of the shocks depends on the way you drive on bumpy roads.

Would need to know what DTC'S - diagnostic trouble codes are stored in the module for the autoride suspension . Hooking up a professional type scan tool ,looking at input data to the module etc... Looking at a wiring diagram an testing electrical circuit's using a DMM - digital multi-meter . Reading how the system works ,what all involved in making the system work . This is how a professional Tech would go about diagnosing this .

The automatic level control (ALC) system maintains a desired rear suspension position under all types of towing, hauling and loading conditions. The following components are involved in the operation of the ALC system:
• Air line tubing--Pressurized air from the ALC compressor is pumped to each of the rear shocks via air line tubing.
• Air drier--Pressurized air from the compressor is run through a drier containing a moisture absorbing chemical preventing water accumulation in the rear shocks.
• Compressor--Supplies pressurized air to the rear shocks
• Compressor motor relay--The relay supplies battery positive voltage to the ALC compressor motor.
• Pressure sensor--The electronic suspension control module (ESCM) module provides a 5-volt reference and low reference to the ALC pressure sensor. The module receives the signal voltage that is relative to the air pressure applied to the rear shocks.
• ESCM--Controls the ALC system and electronic suspension control (ESC) system and detects failures in both. The module monitors inputs from the position sensors, and pressure sensor to determine when to raise and lower the vehicle to trim height as the vehicle is loaded or unloaded. The module limits pump activation to 255 seconds to prevent thermal damage.
• Exhaust valve--An electric solenoid activated by the ESCM to vent air pressure from the rear shocks.
• Left and right rear suspension position sensors--The module provides a 5-volt reference and low reference to all 4 of the body-to-wheel suspension position sensors. The sensors send the ESCM a signal voltage that is relative to the rear suspension ride height
• Left and right rear shock absorbers with internal air chambers and dampers--Dampens the rear suspension and maintains trim height depending on the air pressure applied.

Yes, you can just put regular shocks on the back,just make sure you get shocks that have the same length as your original ones and that are from a explorer without air suspension.That way you wont have the back end of the car riding too low or bottoming out.

Shock Absorber -The rear already has air shocks on the 1999 Cadillac Deville: REMOVAL & INSTALLATION Rear

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Remove or disconnect the following:
   • Rear wheel Fig. 1: Exploded view of the rear shock absorber mounting
     
     
   • Negative battery cable
   • Shock absorber electrical connector from the rear suspension support, If equipped
3. Support the lower control arm with a jack to relieve the tension on the shock absorber.
4. Remove or disconnect the following:
   • Lower shock absorber mounting bolt and nut
   • Upper mounting nut, retainer, and insulator
   • Shock absorber compress by hand and remove through the upper control arm
   To install:
   
5. Position the top of the shock absorber with the insulator attached into the suspension support.
6. Install or connect the following:
   • Upper shock insulator, retainer and nut. Torque the nut to 55 ft. lbs. (74 Nm).
   • Shock absorber lower mounting nut/bolt. Torque the nut to 75 ft. lbs. (102 Nm).
   • Shock absorber electrical connector to the rear suspension support, if equipped
   • Rear wheel
   • Negative battery cable

Service Ride Control means one or some of your shocks or struts are worn and may need replacing. The price for new ones is not cheap,

Yes you can replace with regular shocks. You will want to remove the fuse so the pump no longer runs and you will be OK.
Good luck.

have front suspension checked that truck has air suspension, should be half decite ride, some have shocks in the front maybe those are bad,good luck.

Thr front will be MacPherson struts, a shock absorber surrounded by a coil spring looking set-up.


FOR THE REAR:
If you have front wheel drive and you have Electronic Ride Control (ERC), then the rear suspension has "super lift air shocks".

If you have all wheel drive, then you have struts in the rear suspension.

Does help any?

Removal & Installation

1. Remove the tire and wheel assembly.
2. Support the control arm with a jack stand.
   
   Fig. Use support bracket tool J-23028-01 mounted on a jack to support the rear lower control arm
   
3. Remove or disconnect the following:
   
   Electronic Ride Control (ELC) air tube from the shock Two bolts securing the shock to the control arm Trunk trim to gain access to the shock upper mounting nuts. Cover, the two nuts, and the reinforcement from the top of the shock Shock from the vehicle
   
   Fig. Remove the cover to gain access to the upper shock absorber mounting components-rear suspension
   
   
   Fig. Exploded view of the lower shock absorber mounting to the knuckle assembly-rear suspension
   
   

To install:
Install or connect the following:

Shock, reinforcement, and the two nuts. Tighten the mounting nuts to 15 ft. lbs. (20 Nm). Shock cover Trunk trim Shock-to-control arm bolts and tighten the bolts to 18 ft. lbs. (24 Nm) ELC air tube to the shock. Tire and wheel assembly