Diagnostic Test

DTC IS ACTIVE
1. Start the engine and allow it to idle for at least 60 seconds.
  WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hand near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
2. With a scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
2/2 OXYGEN SENSOR

Fig 1: Measuring Resistance Of O2 Sensor Heater Element Across Oxygen Sensor Connector Between Heater Control Terminal And Ground Terminal
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
  NOTE: Allow the sensor to cool to ambient temperature before continuing. The voltage should stabilize between 4.6 and 5.0 volts.
2. Disconnect the 2/2 Oxygen Sensor harness connector.
3. Measure the resistance of the O2 sensor heater element across the 2/2 Oxygen Sensor connector between the heater control terminal and the ground terminal.
  NOTE: The resistance of the heater element will vary according to temperature and should be measured at 70°F (21.1°C).
  
  Is the resistance between 2.0 and 30.0 Ohms?
  
  Yes
  - Go to step 3
  No
  - Replace the 2/2 Oxygen Sensor in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K399) O2 2/2 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE

Fig 2: Measuring Voltage Of O2 Heater Control Circuit In Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K399) O2 2/2 Heater Control circuit in the 2/2 Oxygen Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K399) O2 2/2 Heater Control circuit for a short to voltage.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
(K399) O2 2/2 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 3: Measuring Resistance Of O2 Heater Control Circuit Between Oxygen Sensor Harness Connector And Appropriate Terminal Of PCM Pinout Box 8815
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
  CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install the PCM Pinout Box 8815 to perform diagnosis.
2. Measure the resistance of the (K399) O2 2/2 Heater Control circuit between the 2/2 Oxygen Sensor harness connector and the appropriate terminal of PCM Pinout Box 8815.
  Is the resistance below 0.5 of an Ohm?
  
  Yes
  - Go to step 5
  No
  - Repair the (K399) O2 2/2 Heater Control circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(Z904/Z920) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 4: Using 12-Volt Test Light Connected To 12 Volts To Check Ground Circuit In Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Using a 12-volt test light connected to 12 volts, check the (Z904/Z920) Ground circuit in the 2/2 Oxygen Sensor harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 6
  No
  - Repair the (Z904/Z920) Ground circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/2 Oxygen Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .