3. O2 Signal Circuit

Turn the ignition off

Disconnect the O2 Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage on the O2 Signal circuit at the O2 Sensor harness connector.

Fig 1: Measuring Voltage Of O2 Signal Circuit At O2 Sensor Harness Connector

Courtesy of DAIMLERCHRYSLER CORP.

Is the voltage approximately 0.47 volt?

Yes >> Go To 4
No >> Check the O2 Signal circuit for damage, short to ground, open, or short to voltage. If OK, replace and program the Powertrain Control Module. See ELECTRONIC CONTROL MODULES article.
See POWERTRAIN VERIFICATION TEST - VER 2 .