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. Refer to INTERMITTENT CONDITION - 6.7L .
CHECK THE (K423) DEF PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE

Fig 1: Checking DEF Pressure Sensor Signal Circuit For A Short To Voltage
Courtesy of CHRYSLER LLC
1. Turn ignition off.
2. Disconnect the DEF Supply Pump harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K423) DEF Pressure Sensor Signal circuit at the DEF Supply Pump harness connector.
  Does the voltage measure above 5.1 Volts?
  
  Yes
  - Repair the (K423) DEF Pressure Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
  No
  - Go To 4.
DEF PRESSURE SENSOR
1. Turn the ignition off.
2. Connect a jumper between the (K423) DEF Pressure Sensor Signal circuit and the (K424) DEF Pressure Sensor Ground circuit at the DEF Supply Pump harness connector.
3. Turn the ignition on, engine not running.
4. With the scan tool check for DTCs.
  Did DTC P204C set as active after shorting the circuits together?
  
  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 4.
CHECK FOR THE (K423) DEF PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K422) DEF PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT

Fig 2: Checking DEF Pressure Sensor Signal Circuit For A Short
Courtesy of CHRYSLER LLC
1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between the (K423) DEF Pressure Sensor Signal circuit and the (K422) DEF Pressure Sensor 5-Volt Supply circuit at the DEF Supply Pump harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 5.
  No
  - Repair the short between the (K423) DEF Pressure Sensor Signal circuit and the (K422) DEF Pressure Sensor 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
CHECK THE (K423) DEF PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE

Fig 3: Checking DEF Pressure Sensor Signal Circuit For An Open/High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K423) DEF Pressure Sensor Signal circuit at the DEF Supply Pump harness connector and the DEF Dosing Control Unit C1 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6.
  No
  - Repair the (K423) DEF Pressure Sensor Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
CHECK THE (K424) DEF PRESSURE SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE

Fig 4: Checking DEF Pressure Sensor Ground Circuit For An Open/High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K424) DEF Pressure Sensor Ground circuit at the DEF Supply Pump harness connector and the DEF Dosing Control Unit C1 harness connector.
  Is the resistance below 5.0 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 (K424) DEF Pressure Sensor Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .