Inspection Procedures

1. Connect a Hi-Scan (Pro) to the data link connector.
2. Turn ignition switch to ON position and monitor any other DTCs.

   Are any other DTCs also set? 

No: Go to next

Yes: Do all repairs associated with those codes before proceeding with this procedure.

1. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

   Are all connectors good? 

Yes: Go to next

No: Repair or replace it.

1. Check intake and exhaust system for vacuum leakage.

   Is any leakage present? 

No: Go to next

Yes: Repair it.

1. Start engine and check engine RPM decrease when disconnecting each injector connector in sequence.

   Is there any cylinder with no change in RPM or only a small change in RPM? 

Yes: Go to next

No: Repair or replace it.

1. Start engine with the fuel pump disconnected and wait until stopping by itself to release fuel pressure.
2. Attach fuel pressure gauge to fuel delivery pipe.
3. Start engine and check fuel pressure at idle.

• Refer to  FUEL PRESSURE TEST   . 

  Is fuel line pressure within specification? 

Yes: Go to next

No: Check fuel delivery system. Refer to FUEL DELIVERY SYSTEM  .

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.

• Refer to  SIGNAL WAVEFORM   for more information. 

Is the rear HO2S signal normal? 

Yes: Proceed with ECM PROBLEM PROCEDURE  .

No: Replace HO2S.