Dodge 2004 Neon SX2 Diagnostic Manual page 442

DRIVEABILITY - NGC
P0171-FUEL SYSTEM 1/1 LEAN —
TEST
9 Ignition on, engine not running.
Disconnect the O2 Sensor harness connector.
With the DRBIII , monitor the O2 Sensor voltage.
The O2 Sensor voltage should read 5.0 volts on the DRBIII with the connector
disconnected.
Using a jumper wire, jump the O2 Signal circuit to the O2 Return circuit at the O2
Sensor harness connector.
NOTE: The voltage should drop from 5.0 volts to 2.5 volts with the jumper
wire in place.
Did the O2 Sensor volts change from 5.0 volts to 2.5 volts?
Yes → Replace the O2 Sensor
→ Go To 10
No
10 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 voltage above 4.8 volts?
Yes → Go To 11
→ Check the O2 Signal circuit for a short to ground, open, or short
No
11 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 → Check the fuel system for contaminants. Also, check the exhaust
→ Check the O2 Return circuit for a short to ground, open, or short
No
ACTION
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
to voltage. Inspect the O2 Sensor connector and the PCM harness
connector. If OK, replace and program the Powertrain Control
Module in accordance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
system for any leaks.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
to voltage. Inspect the O2 Sensor connector and the PCM harness
connector. If OK, replace and program the Powertrain Control
Module in accordance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5 - NGC.
Continued
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APPLICABILITY
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