Diagnostic Test

DTC IS ACTIVE
NOTE: If an O2 sensor signal circuit is shorted to voltage, all O2 sensor voltage readings displayed on the scan tool will be approximately 5.0 volts. Diagnose the sensor that set the most current DTC.
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 .
(K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Measuring Voltage Of O2 Sensor Signal Circuit In Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the 2/2 Oxygen Sensor harness connector.
3. Disconnect the Powertrain Control Module (PCM) harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (K243) O2 2/2 Signal circuit in the 2/2 Oxygen Sensor harness connector.
  NOTE: Measure the voltage in reference to ground, not the (K904) O2 Return (Down) circuit.
  
  Is there any voltage present?
  
  Yes
  - Repair the (K243) O2 2/2 Signal 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 3
(K904) O2 RETURN (DOWN) CIRCUIT SHORTED TO VOLTAGE

Fig 2: Measuring Voltage On O2 Sensor Return (Down) Circuit In Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Measure the voltage on the (K904) O2 Return (Down) circuit in the 2/2 Oxygen Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K904) O2 Return (Down) 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
(K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (K399) O2 2/2 HEATER CONTROL CIRCUIT

Fig 3: Measuring Resistance Between O2 Sensor Signal Circuit And O2 Sensor Heater Control Circuit Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between the (K243) O2 2/2 Signal circuit and the (K399) O2 2/2 Heater Control circuit the 2/2 Oxygen Sensor harness connector.
  Is the resistance below 100.0 Ohms?
  
  Yes
  - Repair the (K243) O2 2/2 Signal circuit for a short to the (K399) O2 2/2 Heater Control circuit.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
2/2 OXYGEN SENSOR

Fig 4: Oxygen Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Connect the Powertrain Control Module (PCM) harness connector.
3. Connect a jumper wire between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return (Down) circuit in the 2/2 Oxygen Sensor harness connector.
4. Turn the ignition on.
5. With a scan tool, monitor the 2/2 Oxygen Sensor voltage.
  Is the voltage between 2.3 and 2.7 volts with the jumper wire in place?
  
  Yes
  - 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 .
  No
  - Go to step 6
(K243) O2 2/2 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 5: Measuring Resistance Of O2 Sensor Signal Circuit Between Oxygen Sensor Harness Connector And Appropriate Terminal Of PCM Pinout Box 8815
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. If necessary, remove the jumper wire from between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return (Down) circuit in the 2/2 Oxygen Sensor harness connector.
3. Disconnect the Powertrain Control Module (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 8815 to perform diagnosis.
4. Measure the resistance of the (K243) O2 2/2 Signal circuit between the 2/2 Oxygen Sensor harness connector and the appropriate terminal of PCM Pinout Box 8815.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 7
  No
  - Repair the (K243) O2 2/2 Signal circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K904) O2 RETURN (DOWN) CIRCUIT OPEN OR HIGH RESISTANCE

Fig 6: Measuring Resistance Of O2 Sensor Return (Down) Circuit Between Oxygen Sensor Harness Connector And Appropriate Terminal Of PCM Pinout Box 8815
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (K904) O2 Return (Down) circuit between the 2/2 Oxygen Sensor harness connector and the appropriate terminal of PCM Pinout Box 8815.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 8
  No
  - Repair the (K904) O2 Return (Down) 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 .