Diagnostic Test

O2 SENSOR HEATER OPERATION
1. Turn the ignition off.
  NOTE: Wait a minimum of 8 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 a scan tool, actuate the O2 Heater Test.
4. With a scan tool, monitor 2/2 O2 Sensor voltage for at least 2 minutes.
  Does the voltage stay above 4.5 volts?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
O2 SENSOR HEATER ELEMENT
1. Turn the ignition off.
  NOTE: Allow the O2 sensor to cool down to room temperature.
2. Disconnect the 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 step 3
  No
  - Verify that there is good pin to terminal contact in the 2/2 Oxygen Sensor and Powertrain Control Module connectors. If OK, replace the 2/2 O2 Sensor.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K399) O2 2/2 HEATER CONTROL CIRCUIT OPEN

Fig 1: Checking O2 Sensor Heater Control Circuit
Courtesy of CHRYSLER 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 PCM Pinout Box 8815 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 special tool #8815.
  Is the resistance below 0.5 of an ohm?
  
  Yes
  - Go to step 4
  No
  - Repair the excessive resistance in the (K399) O2 2/2 Heater Control circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(Z42) O2 2/2 HEATER GROUND CIRCUIT OPEN

Fig 2: Checking O2 Sensor Heater Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between ground and the (Z42) O2 2/2 Heater ground circuit in the O2 Sensor harness connector.
  Is the resistance below 0.5 of an ohm?
  
  Yes
  - Go to step 5
  No
  - Repair the excessive resistance in the (Z42) O2 2/2 Heater ground circuit.
  - Perform the POWERTRAIN 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 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 Oxygen Sensor and Powertrain Control Module connectors.
4. Refer to any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module per Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .