Diagnostic Test

O2 SENSOR HEATER OPERATION
1. Turn the ignition off.
  NOTE:
  Wait a minimum of eight minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize between 4.6 and 5.0 Volts.
2. Ignition on, engine not running.
3. With the scan tool, perform the 2/2 O2 Sensor Heater Test.
4. With the scan tool, monitor 2/2 O2 Sensor voltage for at least two minutes.
  Does the voltage stay above 4.5 Volts?
  
  Yes
  - Go To 2.
  No
  - Perform the INTERMITTENT DTC diagnostic procedure. Refer to 3.7L - INTERMITTENT CONDITION .
O2 SENSOR HEATER ELEMENT
1. Turn the ignition off.
  NOTE:
  Allow the O2 sensor to cool down to room temperature.
2. Disconnect the 2/2 O2 Sensor harness connector.
3. Measure the resistance of the 2/2 O2 Heater Element, between the O2 Heater Control terminal and the O2 Heater ground terminal in the O2 Sensor connector.
  NOTE:
  O2 Heater Element resistance values should be measured at 21.1° C (70° F). The resistance value will vary with different temperature values.
  
  Is the resistance of the O2 Sensor Heater Element between 2.0 and 30.0 Ohms?
  
  Yes
  - Go To 3.
  No
  - Verify that there is good pin to terminal contact in the Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/2 O2 Sensor.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.7L - POWERTRAIN VERIFICATION TEST .
(K399) O2 2/2 HEATER CONTROL CIRCUIT FOR AN OPEN

Fig 1: Checking O2 Sensor Heater Control Circuit For Excessive Resistance
Courtesy of CHRYSLER GROUP, LLC
1. Disconnect the C3 PCM harness connector.
  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 (special tool #8815A, Kit, NGC, 38 Position) to perform diagnosis.
2. Measure the resistance of the (K399) O2 2/2 Heater Control circuit from the O2 harness connector to the appropriate terminal of PCM Pinout Box (special tool #8815A, Kit, NGC, 38 Position).
  Is the resistance below 0.5 of an Ohm?
  
  Yes
  - Go To 4.
  No
  - Repair the excessive resistance in the (K399) O2 2/2 Heater Control circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.7L - POWERTRAIN VERIFICATION TEST .
(Z933) O2 2/2 HEATER GROUND CIRCUIT FOR AN OPEN

Fig 2: Checking O2 Sensor Heater Ground Circuit For An Open
Courtesy of CHRYSLER GROUP, LLC
1. Using a 12-volt test light connected to 12 Volts, check the (Z933) 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 5.
  No
  - Repair the excessive resistance in the (Z933) O2 2/2 Heater ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.7L - POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 2/2 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. Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.7L - POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to 3.7L - POWERTRAIN VERIFICATION TEST .