Dodge 2004 Neon SX2 Diagnostic Manual page 429

P0131-O2 SENSOR 1/1 VOLTAGE LOW —
TEST
1 NOTE: If one of the O2 Sensors Signal or Return circuits are shorted to
ground, the DRBIII will display all O2 Sensor voltage readings low. The O2
Sensor that is shorted to ground will display a voltage reading near or at 0
volts.
NOTE: It is important to perform the diagnostics on the O2 Sensor that set
the DTC.
NOTE: After the repairs have been made, verify proper O2 Sensor operation.
If all the O2 Sensor voltage readings have not returned to normal, follow the
diagnostic procedure for the remaining O2 Sensors.
Start the engine.
Allow the engine to reach normal operating temperature.
With the DRBIII , read the O2 Sensor voltage.
Is the voltage below 2.52 volts?
Yes → Go To 2
→ Refer to the INTERMITTENT CONDITION symptom in the
No
2 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Ignition on, engine not running.
With the DRBIII , monitor the O2 Sensor voltage.
Is the O2 Sensor voltage above 4.8 volts?
Yes → Go To 3
→ Go To 5
No
3 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the O2 Return circuit in the O2 Sensor harness connector.
Is the voltage at 2.5 volts?
Yes → Replace the O2 Sensor.
→ Go To 4
No
4 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance between ground and the O2 Return circuit in the O2 Sensor
harness connector.
Is the resistance below 100 ohms?
Yes → Repair the short to ground in the O2 Return circuit.
→ NOTE: Before continuing, check the PCM harness connector
No
ACTION
Driveability category.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
terminals for corrosion, damage, or terminal push out. Repair as
necessary. Replace and program the Powertrain Control Module
in accordance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
DRIVEABILITY - NGC
Continued
93
APPLICABILITY
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