Diagnostic Test

1/1 OXYGEN SENSOR HEATER CONTROL OPERATION
Turn the ignition off.

NOTE: Wait a minimum of 8 minutes to allow the sensor to cool down before continuing. The 1/1 Oxygen Sensor Volts should stabilize between 2.47 and 2.52 volts.

Turn the ignition on.

With a scan tool, actuate the 1/1 Oxygen Sensor heater control.

With the scan tool, monitor 1/1 Oxygen Sensor Volts for at least 2 minutes.

Does the voltage stay between 2.47 and 2.52 volts?

Yes
1. Go to 2.
No
1. Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.
1/1 OXYGEN SENSOR HARNESS AND CONNECTORS
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 1/1 Oxygen Sensor and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 3.
1/1 OXYGEN SENSOR

Fig 1: Checking Resistance Of O2 Sensor Heater Element
Courtesy of CHRYSLER LLC

Turn the ignition off.

NOTE: Wait a minimum of 8 minutes to allow the sensor to cool down before continuing.

Disconnect the 1/1 Oxygen Sensor harness connector.

Measure the resistance of the heater element across the 1/1 Oxygen Sensor connector between the heater control terminal and the ground terminal.

NOTE: The O2 heater element resistance should be measured at 70° F (21.1° C). The resistance value will vary at different temperatures.

Is the resistance between 3.0 and 30.0 ohms?

Yes
1. Go to 4.
No
1. Replace the 1/1 Oxygen Sensor.
2. Perform PCM VERIFICATION TEST .
(K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 2: Measuring The Resistance Of The O2 1/1 Heater Control Circuit Between The 1/1 O2 Sensor Harness Connector And The Appropriate Terminal Of Special Tool #8815
Courtesy of CHRYSLER LLC

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 Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K99) O2 1/1 Heater Control circuit from the 1/1 Oxygen Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 0.5 ohms?

Yes
1. Go to 5.
No
1. Repair the (K99) O2 1/1 Heater Control circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
(Z901) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 3: Checking The Ground Circuit In The 1/1 O2 Sensor Harness Connector Using A 12 Volt Test Light Connected To 12 Volts
Courtesy of CHRYSLER LLC

Using a 12 volt test light connected to 12 volts, check the (Z901) 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 6.
No
1. Repair the (Z901) Ground circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 1/1 Oxygen Sensor and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .