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 ACTIVE
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).
3. Turn the ignition off.
4. Start the engine and let it run.
  NOTE:
  The Seat Vent should be in the off position and remain off or the results of the test will be invalid.
5. Ignition on, engine running.
6. With the scan tool, read Heated Seat Module (HSM) DTCs.
  Does the scan tool show this DTC as active?
  
  Yes
  - Go To 2
  No
  - Go To 4
CHECK THE (P421) LEFT SEAT VENT FEED CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the HSM C5 harness connector.
3. Start the engine and let it run.
4. Measure the voltage between ground and the (P421) Left Seat Vent Feed circuit at the HSM C5 harness connector.
  Is the voltage 5.0 volts or above?
  
  Yes
  - Repair the (P421) Left Seat Vent Feed circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
CHECK THE (P421) LEFT SEAT VENT FEED CIRCUIT FOR A SHORT TO VOLTAGE DURING SEAT ADJUSTMENT
1. Measure the voltage between ground and the (P421) Left Seat Vent Feed circuit at the HSM C5 harness connector while adjusting the seat in all positions.
  Is the voltage 5.0 volts or above any time during the seat adjustment?
  
  Yes
  - Repair the (P421) Left Seat Vent Feed circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  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 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. Attempt to reproduce the condition(s) by operating all HSM functions, except for the Left Front Vented Seat, one at a time.
5. With the scan tool, check for any Environmental Data to help identify the conditions in which the DTC was set.
6. 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.