Diagnostic Test

1) O2 SENSOR HEATER OPERATION
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.

Ignition on, engine not running.

With a scan tool, actuate the O2 Heater Test.

With the scan tool, monitor 1/1 O2 Sensor voltage for at least 2 minutes.

Does the voltage stay above 4.5 volts?

Yes
1. Go to 2).
No
1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
2) O2 SENSOR HEATER ELEMENT
Turn the ignition off.

NOTE: Allow the O2 sensor to cool down to room temperature.

Disconnect the O2 Sensor harness connector.

Measure the resistance of the O2 Heater Element across the 1/1 O2 Sensor connector between the O2 Heater Control terminal and the Heater ground terminal.

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
1. Go to 3).
No
1. Replace the O2 Sensor.
2. Perform POWERTRAIN VERIFICATION TEST .
3) (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN

Fig 1: Checking O2 Sensor 1/1 Heater Control Circuit For Open
Courtesy of CHRYSLER LLC

Disconnect the C2 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 Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K99) O2 1/1 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
1. Go to 4).
No
1. Repair the excessive resistance in the (K99) O2 1/1 Heater Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
4) (Z42) O2 1/1 HEATER GROUND CIRCUIT OPEN

Fig 2: Checking O2 Sensor Heater Ground Circuit For Open Or High Resistance
Courtesy of CHRYSLER LLC

Using a 12 volt test light connected to 12 volts, check the (Z42) Ground circuit in the 1/1 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
1. Go to 5).
No
1. Repair the excessive resistance in the (Z42) O2 1/1 Heater ground circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
5) PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

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
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .