Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. Perform any Service Bulletins that may apply.
2. Turn the ignition on.
3. With the scan tool, read ASCM DTCs and record on the repair order.
4. With the scan tool, read and record Environmental Data to help identify the conditions in which the DTC was set.
5. With the scan tool, erase ASCM DTCs.
6. Start the engine.
7. With the scan tool, read ASCM DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the 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 STANDARD PROCEDURE - ASCM VERIFICATION TEST .
AIR SUSPENSION RELAY
1. Turn the ignition off to the lock position.
2. Install a known good relay
3. Ignition on, engine not running.
4. With the scan tool, erase the DTCs.
5. With the scan tool, read the DTCs.
  Is the status still Active for this DTC?
  
  Yes
  - Go To 3
  No
  - Install a new Air Suspension Relay.
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
(Y38) COMPRESSOR RELAY SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Remove the Air Suspension Relay.
3. Disconnect the ASCM C2 harness connector.
4. Measure the resistance of the (Y38) Compressor Relay Signal circuit between the ASCM C2 harness connector and the Air Suspension Relay.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (Y38) Compressor Relay Signal circuit for an open or high resistance.
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  No
  - Go To 4
(Y39) AIR COMPRESSOR RELAY RETURN CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Y39) Compressor Relay Return circuit between the ASCM C2 harness connector and the Air Suspension Relay.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (Y39) Compressor Relay Return circuit for an open or high resistance.
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  No
  - Go To 5
(Y39) AIR COMPRESSOR RELAY RETURN CIRCUIT SHORTED TO GROUND
1. Measure the resistance between ground and the (Y39) Air Compressor Relay Return circuit.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the (Y39) Compressor Relay Return circuit for a short to ground.
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  No
  - Go To 6
(Y38) COMPRESSOR RELAY SIGNAL CIRCUIT SHORTED TO (Y39) AIR COMPRESSOR RELAY RETURN CIRCUIT
1. Disconnect the Power Distribution Center (PDC) C2 harness connector.
2. Measure the resistance between the (Y38) Compressor Relay Signal circuit and the (Y39) Air Compressor Relay Return circuit at the ASCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Repair the (Y38) Compressor Relay Signal circuit for a short to (Y39) Air Compressor Relay Return circuit.
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  No
  - Go To 7
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
  - 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 STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  No
  - Perform the ASCM VERIFICATION TEST. Refer to STANDARD PROCEDURE - ASCM VERIFICATION TEST .
  - Test complete.