Diagnostic Test

ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. With the scan tool, read DTCs. Record DTC and Freeze Frame information.
3. 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 hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
4. With the scan tool, read the active DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2.
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
(K243) O2 2/2 SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the 2/2 O2 Sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, monitor the 2/2 O2 Sensor voltage.
  Is the O2 Sensor voltage between 4.1 and 5.0 Volts?
  
  Yes
  - Go To 3.
  No
  - Go To 5.
O2 SENSOR

Fig 1: Measuring Voltage On O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Measure the voltage on the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector.
  Is the voltage at 2.5 Volts?
  
  Yes
  - 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. Refer to SENSOR, OXYGEN, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4.
(K904) O2 RETURN DOWNSTREAM CIRCUIT SHORTED TO GROUND

Fig 2: Checking O2 Sensor Return Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between ground and the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the (K904) O2 Return Downstream circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8.
(K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: Measuring Resistance Between Ground And O2 Sensor Signal Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C1 and C2 PCM harness connectors.
3. Measure the resistance between ground and the (K243) O2 2/2 Signal circuit in the O2 Sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the (K243) O2 2/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6.
(K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (K904) O2 RETURN DOWNSTREAM CIRCUIT

Fig 4: Measuring Resistance Between O2 Sensor Signal Circuit And O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K243) O2 2/2 Signal circuit and the (K904) O2 Return Downstream circuit in the O2 Sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short between the (K904) O2 Return Downstream circuit and the (K243) O2 2/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7.
(K243) O2 2/2 SIGNAL CIRCUIT SHORTED TO THE (Z903) O2 2/2 HEATER GROUND CIRCUIT

Fig 5: Checking O2 Sensor Signal Circuit For Short To O2 Heater Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K243) O2 2/2 Signal circuit and the (Z903) O2 2/2 Heater ground circuit in the O2 Sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short between the (Z903) O2 2/2 Heater ground circuit and the (K243) O2 2/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8.
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 POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .