Suspension, Brakes and Tires Discussion, Air Ride Control Problem on 1997 STS in Item Specific Cadillac Discussion; Hello, I have a 1997 STS with high miles. The air ride control has failed and
the shocks are pumped ...
Hello, I have a 1997 STS with high miles. The air ride control has failed and
the shocks are pumped up full and hard. I have located the air ride compressor above the rear axle and was thinking of disconnecting its power supply, and crack open a fitting at a shock to bleed off some pressure, install a switch on the dash to activate the pump when needed according to the cargo load. I realized that I won't be able to bleed of the air pressure again without getting under the car to open the fitting at the shock. I would like your input as to the source of the overpressure and try to rehabilate the system to operate correctly. Perhaps the system can be rehabilitated with a replacement or repair of the air exhaust solenoid and valve. I appreciate your help. My email is firstname.lastname@example.org / 507 254 3287
Automobile(s): 2002.5 F55 STS/64500mi, 2004 Ford F150 SuperCab4x4
MD Eastern Shore - Kent Island
Re: Air Ride Control Problem on 1997 STS
The Electronic Level Control (ELC or ALC) uses a single rear level sensor in some models or both rear shock height sensors in others. Either the sensor height link arm or the sensor itself has failed, assuming the compressor still works and does its preload at Engine:START +6 seconds.
Study the entire sticky up at the top of the Seville Forums: "How to pull codes" and teach yourself to get any stored Diagnostic Trouble Codes from your cars' built-in code reader/memory. Return to the page and open the link with "obd2" in the URL - the blue lines in the Master Index will take you to lists of the meanings of any P,B,C, or U codes found.
Now you can start troubleshooting the Level Control system.
The mechanic working on the air ride assumed the ride height sensors were faulty and replaced both - but no change. Next he checked the exhaust release solenoid or relay. He released air pressure by opening a fitting so the car is level with no air pressure in the shocks. The air pump would not run - the 30A fuse is good. He replaced the air pump. No change. He states there are no bad fuses, there are no lights or codes. He is stumped.
I think Dick's problem is the same as mine. The problem is definitely the system failure probably caused by a leak initially, then contamination (usually moisture). The system is clogged somewhere and to fix it needs new shocks, lines, dryer (assuming compressor works). I'm still sitting on it.
Miwise: If the car sits low, it could be the springs or a leak in the system.