Diagnostic Test

O2 SENSOR BELOW 1.5 VOLTS
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With a scan tool, read the 1/2 O2 Sensor voltage.
  Is the voltage below 1.5 volts?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See INTERMITTENT CONDITION .
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
(K141) O2 1/2 SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the 1/2 O2 Sensor harness connector.
3. Ignition on, engine not running.
4. With a scan tool, monitor the 1/2 O2 Sensor voltage.
  Is the 1/2 O2 Sensor voltage above 4.8 volts?
  
  Yes
  - Go to step 3
  No
  - Go to step 5
O2 SENSOR

Fig 1: Measuring Voltage On O2 Sensor Return Circuit
Courtesy of CHRYSLER LLC
1. Measure the voltage on the (K902) O2 Downstream Return circuit in the O2 Sensor harness connector.
  Is the voltage at 2.5 volts?
  
  Yes
  - Replace the O2 Sensor.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Go to step 4
(K902) O2 DOWNSTREAM RETURN CIRCUIT SHORTED TO GROUND

Fig 2: Checking O2 Sensor Downstream Return Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the PCM harness connectors.
3. Measure the resistance between ground and the (K902) O2 Downstream Return circuit in the O2 Sensor harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short to ground in the (K902) O2 Downstream Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Go to step 8
(K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: Checking O2 Sensor 1/2 Signal Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the PCM harness connectors.
3. Measure the resistance between ground and the (K141) O2 1/2 Signal circuit in the O2 Sensor harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short to ground in the (K141) O2 1/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Go to step 6
(K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO (K902) O2 DOWNSTREAM RETURN CIRCUIT

Fig 4: Checking O2 Sensor 1/2 Signal Circuit For Short
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K141) O2 1/2 Signal circuit and the (K902) O2 Downstream Return circuit in the O2 Sensor harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short between the (K902) O2 Downstream Return circuit and the (K141) O2 1/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Go to step 7
(K141) O2 1/2 SIGNAL CIRCUIT SHORTED TO (Z902) O2 1/2 HEATER GROUND CIRCUIT

Fig 5: Checking O2 Sensor 1/2 Signal Circuit For Short
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (K141) O2 1/2 Signal circuit and the (Z902) O2 1/2 Heater ground circuit in the O2 Sensor harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the short between the (Z902) O2 1/2 Heater ground circuit and the (K141) O2 1/2 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Go to step 8
PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module per Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See POWERTRAIN VERIFICATION TEST .