Test Procedure

HU1: CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Is DTC P2279 present?
- Yes: GO to HU2.
- No: For all other DTCs, REFER to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
  For all other symptoms, GO to HU2.
HU2: CHECK THE INTAKE AIR SYSTEM FOR LEAKS, OBSTRUCTIONS AND DAMAGE
- Remove the air cleaner element. Check the air cleaner for restrictions.
- Check for restrictions between the air inlet and the throttle body.
- Are any restriction concerns present?
- Yes: REMOVE the restriction.
  INSTALL a new air cleaner element.
  
  REFER to the INTAKE AIR DISTRIBUTION AND FILTERING -- HYBRID .
  
  CLEAR the DTCs. REPEAT the self-test.
- No: INSTALL the air cleaner element.
  GO to HU3.
HU3: CHECK FOR VACUUM LEAKS
- Listen for vacuum leaks from the following:
  - cracked or punctured inlet air tube
  - loose connections on the inlet air tube at the air cleaner housing or throttle body
  - intake manifold assembly or gasket
  - vacuum supply connectors and hose
- Are any concerns present?
- Yes: REPAIR as necessary.
  CLEAR the DTCs. REPEAT the self-test.
- No: GO to HU4.
HU4: CHECK THE THROTTLE BODY FOR EXCESSIVE WEAR
- Key in OFF position.
- Remove the throttle body assembly. Refer to the FUEL CHARGING AND CONTROLS -- HYBRID .
- Inspect the throttle body for:
  - excessive wear or grooving in the throttle bore
  - misaligned or worn throttle plate
  - excessive gap between the throttle bore and plate
- Are any concerns present?
- Yes: INSTALL a new throttle body assembly.
  REFER to the FUEL CHARGING AND CONTROLS -- HYBRID .
  
  CLEAR the DTCs. REPEAT the self-test.
- No: RETURN to SYMPTOM CHARTS for further direction.