Reading and Clearing Diagnostic Trouble Codes

Fig. 2 Service Bay Diagnostic Procedure, (Part 1 Of 2):

Fig. 2 Service Bay Diagnostic Procedure, (Part 2 Of 2):

Auto/Manual Diagnostic Check

The automatic portion of this test begins with checking the control module for shorts or opens that would create STAR codes 39 through 46, and 68 through 71. If shorts or opens are detected, the automatic portion of the test is over and a STAR code 13, auto test failed, will be displayed. If no shorts or opens are detected, the automatic portion of the test continues. The control module attempts to raise and lower the vehicle to verify that all three height positions can be reached. A normally functioning vehicle will be at trim height by the end of the test. If all three height positions are not reached, the auto test will end and STAR code 13 will be displayed. STAR code 12 will be displayed at the end of the auto test if everything is satisfactory.
After STAR code 12 or 13 is displayed, the control module will check for manual inputs. The manual inputs check the steering sensor and the door circuits. To pass the manual test the control module must detect that all four doors have been opened and closed, and that the steering wheel has been turned at least 1/4 turn in each direction. After the manual test, the tester must be toggled, or the control module will continue to monitor the manual test inputs indefinitely. Either STAR code 11, air suspension normal, or other STAR codes will be displayed.

STAR Code Display

Fig. 3 Diagnostic Codes & Priority Chart:

STAR codes will be automatically displayed after the Auto/Manual Diagnostic Check is completed. Each code detected will be displayed for about 15 seconds. Codes should be recorded at this time, refer to diagnostic code priorities chart, Fig. 3.

NOTE: For code 13, this circuit originates at a 30 amp fuse in the power distribution box. Check the fuse.