Test Procedure
- HU1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Is DTC P0505 or P0506 present?
Yes No GO to HU2. For symptoms without DTCs, GO to HU2.
For all others, RETURN to SYMPTOM CHARTS for further direction. - HU2 CHECK THE INTAKE AIR SYSTEM FOR LEAKS, OBSTRUCTIONS, AND DAMAGE
- Listen for vacuum leaks from the following:
- loose connections on the intake air tube at the air cleaner housing or throttle body
- cracked or punctured intake air tube
- worn gaskets between the mass air flow (MAF) sensor and the air cleaner assembly
- vacuum supply connectors and hose
- intake manifold assembly or gasket
- exhaust gas recirculation (EGR) valve gasket leak to intake manifold
- verify the integrity of the positive crankcase ventilation (PCV) system and the correct PCV valve part number
- correctly seated engine oil dipstick, tube or oil fill cap
- aftermarket accessories and performance modifications
Are any concerns present?
Yes No REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test.RETURN to SYMPTOM CHARTS for further direction. - Listen for vacuum leaks from the following: