No Response From ASCM (Air Suspension Control Module)

WARNING: This page is about a different car, the 2016 RAM 3500 HD and 2016 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS article .

Fig 1: Air Suspension Control Module Circuit Diagram

Courtesy of CHRYSLER GROUP, LLC

Possible Causes
FUSED B(+) CIRCUITS OPEN OR SHORTED
IGNITION RUN/START CONTROL OUTPUT CIRCUIT OPEN OR SHORTED
GROUND CIRCUITS OPEN
CAN C BUS (+) CIRCUIT OPEN
CAN C BUS (-) CIRCUIT OPEN
AIR SUSPENSION CONTROL MODULE (ASCM)

TEST FOR INTERMITTENT CONDITION
NOTE: Check for any TSB(s) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.
1. Turn the ignition on.
  NOTE: Make sure the battery voltage is between 10.0 and 16.0 volts.
2. With the scan tool, read the module status.
  NOTE: Check the BCM for any active CAN DTCs and perform the appropriate diagnostics before proceeding. Refer to BODY CONTROL MODULE (BCM) - DIAGNOSTIC CODE INDEX - 2500 HD & 3500 HD .
  
  Does the scan tool indicate that the module is active on the bus?
  - Perform the Stored Lost Communication DTCs diagnostic procedure. Refer to STORED LOST COMMUNICATION DTCS
  - Go to 2
CHECK (A206) FUSED B(+) CIRCUIT FOR AN OPEN OR SHORT
1. Turn the ignition off.
2. Disconnect the Air Suspension Control Module (ASCM) C2 harness connector.
3. Using a 12-volt test light connected to ground, check the (A206) Fused B(+) circuit.
  Does the test light illuminate brightly?
  - Go to 3
  - Repair the (A206) Fused B(+) circuit for an open or short.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK THE (F944) IGNITION RUN/START RELAY OUTPUT CIRCUIT FOR AN OPEN OR SHORT
NOTE: Install a substitute relay
1. Turn the ignition on.
2. Using a 12-volt test light connected to ground, check the (F944) Ignition Run/Start Relay Output circuit.
  Does the test light illuminate brightly?
  - Go to 4
  - Repair the (F944) Ignition Run/Start Relay Output circuit for an open or short.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK THE (Z906) GROUND CIRCUIT FOR AN OPEN
1. Using a 12-volt test light connected to 12-volts, check the (Z906) Ground circuit.
  Does the test light illuminate brightly for each circuit?
  - Go to 5
  - Repair the (Z906) Ground circuit for an open.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK THE (D151) CAN C BUS (+) CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Air Suspension Control Module (ASCM) C1 harness connector.
3. Disconnect the Star CAN C Dash C13 harness connector.
4. Measure the resistance of the (D151) CAN C Bus (+) circuit between the Star CAN C Dash C13 harness connector and the ASCM C1 harness connector.
  Is resistance below 5.0 Ohms?
  - Go to 6
  - Repair the (D151) CAN C Bus (+) circuit for an open.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
CHECK THE (D150) CAN C BUS (-) CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D150) CAN C Bus (-) circuit between the Star CAN C Dash C13 harness connector and the ASCM C1 harness connector.
  Is resistance below 5.0 Ohms?
  - Replace the Air Suspension Control Module (ASCM) in accordance with the Service Information. Refer to MODULE, AIR SUSPENSION CONTROL .
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .
  - Repair the (D150) CAN C Bus (-) circuit for an open.
  - Perform the ASCM VERIFICATION TEST. Refer to ASCM VERIFICATION TEST .