Inspection Procedure

1. Connect a Hi-Scan (Pro) to the data link connector.
2. Start engine and wait 1 minute.

Does scan tool display DTC P0137?

1. Yes:  Go to next step.
2. No: Problem is intermittent or was repaired and ECM memory was not cleared. See INTERMITTENT PROBLEM INSPECTION PROCEDURE ..

1. Turn ignition switch to OFF position, and then disconnect HO2S and ECM connector.
2. Measure resistance between terminal 1 and 2 of the HO2S harness connector.
3. Measure resistance between terminal 2 of the HO2S harness connector and chassis ground.

   Specification (Resistance): infinite

Does each resistance indicate open?

Fig 1: Checking For Short To Ground In Harness

Courtesy of KIA MOTORS AMERICA, INC.

1. Yes:  Go to next step.
2. No: Repair short in harness or short to chassis ground.

1. Reconnect the HO2S and ECM connectors.
2. Warm up the engine to normal operating temperature.
3. Using a Hi-Scan (Pro), monitor the HO2S signal waveform.
   NOTE:

   • 0.0V when signal line is short to chassis ground

Do the rear HO2S signals fluctuate between 0V and 1V?

1. Yes:  Proceed with ECM PROBLEM INSPECTION PROCEDURE .
2. No: Replace HO2S.