Initial Inspection and Diagnostic Overview

1. Measure distance to floor from center of rear wheel opening.
2. Reset the height sensor time limit accumulators as follows. Failure to perform the following step can result in incorrect diagnosis:
a. On Oldsmobile except Toronado, cycle ignition ``Off'' and ``On.'' Leave ignition ``On'' during testing.
b. On 1982---85 Pontiac and Buick except Riviera, 1985 Electra and Park Avenue, momentarily start engine. Leave ignition ``On'' during testing.
c. On 1982---85 Toronado and Riviera, place shift lever in reverse and cycle engine ``Off'' and ``On.'' Leave ignition ``On'' during testing.
d. On 1982---85 Cadillac, 1985 Buick Electra and Park Avenue, cycle engine ``Off'' and ``On.'' Cycle shift lever from park to reverse to park with ignition in ``On'' position, resetting internal timer during testing.
e. On 1986---87 Cadillac models and Toronado, cycle ignition ``On,'' then ``Off'' to reset system.
3. Apply a load of 300---350 pounds to rear of vehicle.
4. There should be a 14---28 second delay on Cadillac, Toronado, 1982---85 Riviera, 1985 Electra, Park Avenue and 98, or an 8---15 second delay on all other models before compressor turns on and vehicle starts to rise within 3/4 inch on 1982---85 models, or 1 inch on 1986---87 models, of measurement noted in step 1. Failure of the vehicle to return to unloaded dimension can be caused by unusually heavy loading in the trunk which exceeds the capacity of the system. If this type of loading is encountered, the compressor will run for several minutes and then shut off. The excess load should be removed and the test repeated. Follow procedure under step 2 to ensure resetting the height sensor time limit accumulators.
5. Remove load applied in step 3:
a. There should be a 14---28 second delay on Cadillac, Toronado, 1982---85 Riviera, 1985 Electra, Park Avenue and 98, or 8---15 second delay on all other models.
b. Vehicle should lower to within 3/4 inch on (±1 inch on 1986---87 Cadillac models) of measurement taken in step 1 within 1---2 1/2 minutes on 1985 DeVille, Electra, Fleetwood and Park Avenue and all 1986---87 Cadillac models, or in less than 3 1/2 minutes on all other models.
6. If system does not operate as described previously, refer to ``System Diagnosis.''