Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

CHECK IF THE DTC IS CURRENT
NOTE:
Make sure the battery is fully charged and the charging system is operating properly before proceeding.
1. Turn the ignition on.
2. Using a scan tool, record and erase Diagnostic Trouble Codes (DTCs).
  NOTE:
  It is recommended to record any Environmental Data to help identify the conditions in which the DTC was set.
3. Turn the ignition off.
4. Ignition on, engine running.
5. Turn the Vented Seat on and wait at least 12 seconds before proceeding.
6. Using a scan tool, read Heated Seat Module (HSM) DTCs.
  Does the scan tool show this DTC as active?
  
  Yes
  - Go To 2
  No
  - Go To 7
CHECK THE (P421) LEFT SEAT VENT FEED CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the HSM C5 harness connector.
3. Measure the resistance between ground and the (P421) Left Seat Vent Feed circuit in the HSM C5 harness connector.
  Is the resistance below 10K Ohms?
  
  Yes
  - Repair the (P421) Left Seat Vent Feed circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
CHECK THE LEFT VENT SEAT MOTORS
1. Connect a jumper wire between ground and the (P921) Left Seat Vent Return circuit in the HSM C5 harness connector.
2. Connect a fused jumper wire between B(+) and the (P421) Left Seat Vent Feed circuit in the HSM C5 harness connector.
  Are both vent seat motors operative?
  
  Yes
  - Go To 4
  No
  - Inspect the wiring and connectors to the inoperative motor and repair as necessary. If no problems are found, replace the inoperative motor in accordance with the Service Information. Refer to MOTOR, VENTED SEAT, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE AMPERAGE OF THE LEFT VENT SEAT MOTORS
1. Connect a fused jumper wire between B(+) and the (P421) Left Seat Vent Feed circuit in the HSM C5 harness connector.
2. Measure the amperage by connecting an ammeter between ground and the (P921) Left Seat Vent Return circuit in the HSM C5 harness connector.
3. Is the amperage above 1.5 amps?
  
  Yes
  - Go To 5
  No
  - Replace the Heated Seat Module (HSM) in accordance with the Service Information. Refer to MODULE, HEATED SEAT, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE LEFT SEAT CUSHION VENT MOTOR
1. Disconnect the Left Seat Cushion Vent Motor C2 harness connector.
2. Connect a fused jumper wire between B(+) and the (P421) Left Seat Vent Feed circuit in the Left Seat Cushion Vent Motor connector.
3. Measure the amperage by connecting an ammeter between ground and the (P921) Left Seat Vent Return circuit in the Left Seat Cushion Vent Motor connector.
  NOTE:
  Individual vent motors normally operate between 0.4 and 0.5 amps.
  
  Is the amperage above 0.75 amps?
  
  Yes
  - Replace the Seat Cushion Vent Motor in accordance with the Service Information. Refer to MOTOR, VENTED SEAT, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 6
CHECK THE LEFT SEAT BACK VENT MOTOR
1. Disconnect the Left Seat Back Vent Motor C2 harness connector.
2. Connect a fused jumper wire between B(+) and the (P421) Left Seat Vent Feed circuit in the Left Seat Back Vent Motor connector.
3. Measure the amperage by connecting an ammeter between ground and the (P921) Left Seat Vent Return circuit in the Left Seat Back Vent Motor connector.
  Is the amperage above 0.75 amps?
  
  Yes
  - Replace the Seat Back Vent Motor in accordance with the Service Information. Refer to MOTOR, VENTED SEAT, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Repair or replace the left seat wiring harness for a short to another circuit.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle the wiring and connectors while checking for shorted and open circuits. Attempt to reproduce the condition by adjusting the seat(s).
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension. Verify the seat wiring harness is routed correctly to the Heated Seat Module (HSM).
4. With the scan tool, check for any Environmental Data to help identify the conditions in which the DTC was set.
5. Check Service Bulletins for any possible causes that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete.