Functional Test

Functional Test


CAUTION:
Functional test is run only if diagnosis does not identify concern. Excessive use of the functional test could overheat the compressor or damage system electronics.

These tests are run at the end of the Auto/Manual test procedure, and are used as an aid to diagnose the system. The only way to enter the Functional Test is by first running the Auto/Manual test. During the Functional Test the module will attempt to cycle the components as follows:


STAR Code 23: Vent Rear - During this test the control module will attempt to open the vent solenoid valve spring solenoid valves as long as the STAR tester button is depressed. The rear of the vehicle will lower.

STAR Code 26: Compress Rear - During this test the control module will attempt to energize the compressor and open the spring solenoid valves as long as the STAR tester button is depressed. The rear of the vehicle will rise.


NOTE:
The extended use of this test can cause the self-resetting circuit breaker in the compressor to open. If this happens, allow the compressor to cool down for 15 minutes. Then, restart the diagnostic procedures.


NOTE:
Code 26 is normally used to inflate the air spring after installation.


STAR Code 31: Air Compressor Relay Toggle - During this test, the control module will attempt to cycle the compressor relay ON for one second and OFF for one second repeatedly. This cycle will repeat for as long as the STAR tester button is depressed. The compressor will be heard cycling ON and OFF if this test is successful.


STAR Code 32: Vent Solenoid Valve Toggle - During this test, the vent solenoid valve is opened for one second, then closed for one second. This cycle will repeat for as long as the STAR tester button is depressed. The vent solenoid valve in the air compressor will be heard cycling ON and OFF if this test is successful.


STAR Code 33: Air Spring Solenoid Valve Toggle - During this test, both air spring solenoids will be opened for one second, then closed for one second repeatedly. This cycle will repeat for as long as the STAR tester button is. depressed. The module cannot turn one spring solenoid on without turning the other solenoid on (Circuits 41.6 and 429 are tied together inside the control module). To verify that both spring solenoids operate; raise the vehicle on a hoist. Do not turn the air suspension switch OFF. Remain in Functional Test 33. Then, touch each solenoid to verify that it is cycling ON and OFF.