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.

ACTIVE DTC
NOTE:
If DTC P21CB or P21CC are also active, diagnose and repair that DTC before continuing with this test procedure.
1. Turn the ignition on, engine not running.
2. With the scan tool, actuate the DEF Line Heater or Tank Heater.
3. With the scan tool, navigate to Actuator Tests and actuate the DEF Line Heater or Tank Heater Override Test.
4. With the scan tool, View DTCs.
  Is the DTC Active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION - 6.7L. Refer to STANDARD PROCEDURE .
CHECK THE (F203) SCR MODULE HEATER SUPPLY CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Turn the ignition off for 90 seconds.
2. Remove the SCR Relay 1 from the auxiliary PDC.
3. Disconnect the DEF Dosing Control Unit C1 harness connector.
4. Disconnect the PCM C2 harness connector.
5. Measure the resistance between the (F203) SCR Module Heater Supply circuit and all other circuits at the DEF Dosing Control Unit C1 harness connector.
  Is the resistance above 10k Ohms between the (F203) SCR Module Heater Supply circuit and all other circuits?
  
  Yes
  - Go To 3
  No
  - Repair the short between the (F203) SCR Module Heater Supply circuit and the circuit that measured below 10k Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to STANDARD PROCEDURE .
CHECK THE SCR RELAY 1
1. Replace the SCR Relay 1 with a known good relay.
2. Turn the ignition on, engine not running.
3. With the scan tool, erase DTCs.
4. With the scan tool, navigate to Actuator Tests and actuate the DEF Line Heater or Tank Heater Override Test.
5. With the scan tool, View DTCs.
  Did the DTC return?
  
  Yes
  - Replace the DEF Dosing Control Unit in accordance with the service information. Refer to UNIT, DIESEL EXHAUST FLUID DOSING CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to STANDARD PROCEDURE .
  No
  - Replace the SCR Relay 1.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to STANDARD PROCEDURE .