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. With the scan tool, read DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Start the engine.
5. Turn the Left Rear Heated Seat on.
6. With the scan tool, read HSM DTCs.
  Is the same DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (P177) LEFT REAR SEAT HEATER CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Heated Seat Module (HSM) C3 harness connector.
3. Disconnect the Left Rear Seat Cushion Heater harness connector.
4. Check for continuity between ground and the (P177) Left Rear Seat Heater Control circuit at the HSM C3 harness connector.
  Is there continuity between ground and the (P177) Left Rear Seat Heater Control circuit?
  
  Yes
  - Repair the (P177) Left Rear Seat Heater Control circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (P177) LEFT REAR SEAT HEATER CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Check for continuity between the (P177) Left Rear Seat Heater Control circuit and all other circuits in the HSM C3 harness connector.
  Is there continuity between the (P177) Left Rear Seat Heater Control circuit and any other circuit?
  
  Yes
  - Repair the (P177) Left Rear Seat Heater Control circuit for a short to another circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE LEFT REAR SEAT CUSHION HEATER ELEMENT RESISTANCE
1. Measure the resistance of the Left Rear Seat Cushion Heater element between the (P177) Left Rear Seat Heater Control circuit and the (Z909) Ground circuit at the Left Rear Seat Cushion Heater component connector.
  Is the resistance between 7.1 and 10.6 Ohms?
  
  Yes
  - Go To 5
  No
  - Replace the Left Rear Seat Cushion Heater element in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect all HSM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all HSM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
11. With the scan tool, read HSM DTCs.
  Is the same DTC active?
  
  Yes
  - Replace the Heated Seat Module (HSM) in accordance with the Service Information. Refer to MODULE, HEATED SEAT (HSM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repairing the wiring harness or connections corrected the problem.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .