Diagnostic Tests

WARNING: This page is about a different car, the 2006 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

1) GOOD TRIP INDICATED
Turn the ignition on.

With the scan tool, read DTCs.

Does the Good Trip Counter Indicator display NO?

Yes
1. Go To 3).
No
1. Go To 2).
2) O2 SENSOR HEATER OPERATION
NOTE: Allow the O2 Sensor voltage to stabilize to between 0.4 to 0.6 volts before continuing the test.

Turn the ignition on.

With the scan tool, actuate the O2 Heater Relay.

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

Does the voltage stay between 0.4 and 0.6 volt?

Yes
1. Go To 3).
No
1. Refer to the INTERMITTENT CONDITION diagnostic procedure.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
3) O2 HEATER ELEMENT
NOTE: Allow the O2 Sensor voltage to stabilize to between 0.4 to 0.6 volts before continuing the test.

Turn the ignition off.

Disconnect the O2 Sensor harness connector.

Measure the resistance across the O2 Sensor Heater element at the component side of the connector.

NOTE: Heater Resistance Specification for 1/1 and 1/2 O2 Sensor is from 3 to 20 ohms.

Is the O2 Sensor Heater element within specification?

Yes
1. Go To 4).
No
1. Replace the O2 Sensor.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
4) (K299) O2 SENSOR HEATER CONTROL CIRCUIT SHORT TO VOLTAGE

Fig 1: MEASURING VOLTAGE OF THE O2 SENSOR HEATER CONTROL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the O2 Sensor harness connector.

Disconnect the PCM harness connector.

Turn the ignition on.

Measure the voltage of the O2 Sensor Heater Control circuit in the (K299) O2 Sensor harness connector.

Is the voltage above 1.0 volt?

Yes
1. Repair the (K299) O2 Sensor Heater Control circuit for a short to voltage.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 5).
5) (K299) O2 SENSOR HEATER CONTROL CIRCUIT SHORTED TO (K342) ASD RELAY OUTPUT CIRCUIT

Fig 2: MEASURING RESISTANCE OF THE O2 SENSOR HEATER CONTROL CIRCUIT AND THE ASD RELAY OUTPUT CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the O2 Sensor harness connector.

Disconnect the PCM harness connector.

Measure the resistance between the (K299) O2 Sensor Heater Control circuit and the (K342) ASD Relay Output circuit in the O2 Sensors harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Repair the (K299) O2 Sensor Heater Control circuit short to the (K342) ASD Relay Output circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 6).
6) PCM
NOTE: Before Continuing: Disconnect the PCM harness connector and check the related wiring 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.

If there are no possible causes remaining, view repair.

Repair
1. Replace and program the Powertrain Control Module in accordance with the Service Information. (Refer to STANDARD PROCEDURE - PCM/ECM/SKREEM PROGRAMMING) .
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .