Diagnostic Test

CHECK FOR AIR SUSPENSION CONTROL MODULE (ASCM) DTCS
1. Turn the ignition on.
2. With the scan tool, check for DTC C15D9-00-Low Air Mass.
  Is DTC C15D9-00 present?
  
  Yes
  - Perform the C15D9-00 DTC(s) before continuing with this diagnostic procedure. Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 2
CHECK FOR AN ACTIVE DTC
1. Perform any Service Bulletins that may apply.
2. Turn the ignition off.
3. Wait 10 minutes.
4. Turn the ignition on.
5. With the scan tool, read ASCM DTCs and record on the repair order.
6. With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.
7. Start the engine.
8. With the scan tool, erase ASCM DTCs.
9. Place the vehicle in "Transport Mode" switch to ON.
  NOTE:
  Transport Mode can be accessed through Settings>Suspension option through the center display.
10. Wait 45 seconds.
11. With the vehicle in "Transport Mode" switch to OFF.
12. Wait 45 seconds.
13. With the scan tool, read ASCM DTCs.
  Is the DTC active?
  
  Yes
  - Go To 3
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAMS as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK AIR COMPRESSOR TEMPERATURE SENSOR
Is the temperature above 176°F (80°C)?

Yes
- Go To 4
No
- Go To 6
CHECK AIR LINES FOR LEAKS OR RESTRICTIONS
1. With Scan Tool, Run "Filling Airspring via Reservoir" routine for each airspring (complete filling)
2. If an airspring is slow to fill, to look for the following, refer to AIR SUSPENSION, DIAGNOSIS AND TESTING .
  - Kinks or restrictions in the air lines
  - Leaks in the air lines
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
  No
  - Go To 5
PERFORM RIDE HEIGHT SENSOR ROUTINE
1. Turn the ignition on.
2. Using the scan tool, under "Miscellaneous Functions" perform the Ride Height Sensor routine.
3. With the scan tool, erase ASCM DTCs.
4. Start the engine.
5. With the scan tool, read ASCM DTCs.
  Does the DTC remain active?
  
  Yes
  - Perform the Ride Height Sensor routine again, if still unsuccessful.
  - Go To 6
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAMS as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect the ASCM Module harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Connect the ASCM harness connectors. Be certain that the harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect the related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read ASCM Module DTCs.
  Did the DTC return?
  
  Yes
  - Go to 7
  No
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
  - Test complete.
AIR SUSPENSION VALVE BLOCK
1. Turn the ignition off.
2. Replace the Air Suspension Valve Block in accordance with the Service Information. Refer to COMPRESSOR, AIR, REMOVAL . Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
3. Ignition on.
4. With the scan tool, erase ASCM DTCs.
5. With the scan tool, read ASCM DTCs.
  Does the DTC remain active?
  
  Yes
  - Replace the Air Suspension Control Module (ASCM) in accordance with the Service Information. Refer to MODULE, AIR SUSPENSION CONTROL (ASCM), REMOVAL .
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
  No
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .