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
NOTE:
If DTC P204A is also active, perform the diagnostic procedures for that DTC before continuing with this test.
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 ignition on.
4. With the scan tool check DTCs.
  Did DTC P204D become active with the DEF Supply Pump harness connector disconnected?
  
  Yes
  - Go To 3.
  No
  - 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 .
CHECK THE (K422) DEF PRESSURE SENSOR SUPPLY CIRCUIT FOR AN OPEN OR SHORT TO GROUND

Fig 1: Checking DEF Pressure Sensor Supply Circuit For An Open Or Short To Ground
Courtesy of CHRYSLER LLC
1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between ground and the (K422) DEF Pressure Sensor Supply circuit at the DEF Supply Pump harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 4.
  No
  - Repair the (K422) DEF Pressure Sensor Supply circuit for an open circuit or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
CHECK THE (K423) DEF PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Fig 2: Checking DEF Pressure Sensor Signal Circuit For A Short To Ground
Courtesy of CHRYSLER LLC
1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between ground and the (K423) DEF Pressure Sensor Signal circuit at the DEF Supply Pump harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5.
  No
  - Repair the (K423) DEF Pressure Sensor Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
CHECK FOR THE (K423) DEF PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K424) DEF PRESSURE SENSOR GROUND CIRCUIT

Fig 3: Checking For DEF Pressure Sensor Signal Circuit For A Short
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K423) DEF Pressure Sensor Signal circuit and the (K424) DEF Pressure Sensor Ground circuit at the DEF Supply Pump harness connector.
  Is the resistance above 10k Ohms?
  
  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 short between the (K423) DEF Pressure Sensor Signal circuit and the (K424) DEF Pressure Sensor Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .