Diagnostic Test

WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool check for active DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2.
  No
  - Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Refer to INTERMITTENT CONDITION - 6.7L .
CHECK THE DEF PRESSURE SENSOR
1. Turn the ignition off.
2. Disconnect the DEF Supply Pump harness connector.
3. Turn the ignition on, engine not running.
4. With the scan tool, View DTCs.
  NOTE:
  Other DTCs will also set from unplugging the DEF Pump Assembly. Ignore any DTCs that do not pertain to the DEF Pressure Sensor.
  
  Did DTC P204D set as active after unplugging the connector?
  
  Yes
  - Replace the DEF Supply Pump Assembly in accordance with the service information. Refer to ASSEMBLY, Diesel Exhaust Fluid Pump , Removal .
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
  No
  - Go To 3.
CHECK FOR THE (K422) DEF PRESSURE SENSOR SUPPLY CIRCUIT SHORTED TO ANOTHER CIRCUIT

Fig 1: Checking DEF Pressure Sensor Supply Circuit For A Short To Another Circuit
Courtesy of CHRYSLER LLC
1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between the (K422) DEF Pressure Sensor Supply circuit and all other circuits at the DEF Dosing Control Unit C1 harness connector.
  Is the resistance above 10k Ohms between the (K422) DEF Pressure Sensor Supply circuit and all other circuits?
  
  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 POWERTRAIN VERIFICATION TEST - 6.7L .
  No
  - Repair the (K422) DEF Pressure Sensor Supply circuit for a short to the circuit that measured below 10k Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .